Volume 4 Number 18 14 May 2016 Pages 6655–7074 Journal of M aterials Chemistry A Materials for energy and sustainability www.rsc.org/MaterialsA Emerging Investigators 2016: Novel design strategies for new functional materials ISSN 2050-7488 REVIEW ARTICLE Yabing Qi et al. Organometal halide perovskite thin fi lms and solar cells by vapor deposition Journal of Materials Chemistry A REVIEW View Article Online View Journal | View Issue fi Organometal halide perovskite thin lms and solar M. ence. cells by vapor deposition 2:06:00 Aported Lic C66it9e3this:J.Mater.Chem.A,2016,4, Luis K. Ono,† Matthew R. Leyden,† Shenghao Wang and Yabing Qi* 1n 3 U Organometalhalideperovskites(OHPs)arecurrentlyunderthespotlightaspromisingmaterialsfornew 2023.0 generationlow-cost,high-efficiencysolarcelltechnology.Withinafewyearsofintensiveresearch,the n 2/16/bution sinoclareraseendertgoy-atole-veellecthtraitciitsyopnopwaerrwicthontvheartsoiofneveeffinctiheencbyes(tPcCryEs)tabllainseedsiloicnonOsHoPlarmcealtles.riHaloswheavserr,atphiedrley ed oAttri is plenty of room for further improvements. In particular, the development of protocols to make such wnloadmmons apotteecnhtniaolloingyfaabpripclaictainbgleutnoifoinrdmusstreymisitroanfsppaarraemnotupnetroimvspkoitretafinlcmes.Vaacproosrsblaasregdemareetahso.dInssthhoiswarptaicrlteic,uwlaer 5. Doe Co RAcecceepivteedd61tshtDNeocveemmbbeerr22001155 reviewtherecentprogressofOHPthin-filmfabricationbasedonvaporbaseddepositiontechniques.We ber 201Creativ DOI:10.1039/c5ta08963h dcoisrcruessspotnhdeingindstervuimceenpteartfioornmaanncde.sIpnetchifiecoufetlaotoukr,esweoofuetlaincehthveapvoarp-obrasdeedpomsiteiothnordelaatsedwtoelplicassthiatst ma www.rsc.org/MaterialsA warrantfurtherinvestigation. ceer ed Dn n 01 sed u 1. Introduction cells with the highest power conversion efficiency (PCE) of e. Published oarticle is licen Oaeffisrgtchaineenomcmyoesstotallpahrroacmleildilsetienpcgehrncoaovnslokdgiitydeath(tOeaHtfoiPsr)ctsohomelapnraectxeitbllglseehnwaeivtrhaetleioomwne-chrogigeshtd, ws(cid:1)ihl2i0icTco.hh1ne%issteoowrlnmaelrryepcaeealrflceoshwv.siepkveietredcereninftelraoswtsoehroatrhctaattniemgthoeerysbpoeafsntmsaointfegrflioeaulcsrrytyshetaaatlrlcsia,n6n,e7 s Articl This lfoawbr-itceamtipoenrautusirnegper.ogc.euslstirnags,oniecxisbplerasyu-cbosattriantges,1,panridntlianrgg,e2-arorella- cbreyrsetaplressterunctetudrbeyttoheoxbiudieldpinergobvslokcitkeosfsAuBcXh3aasndcaaldcioupmtatsitiamnialater s e cc to-roll,3 and vapor deposition techniques.4,5 Laboratory scale (CaTiO3).Afewreviewpapershavebeenpublishedonoxideand A n halide based perovskites with emphasis on solar cell applica- e Op tion.8–20IntheparticularcaseofOHPs,thehalideanions(X¼I, EnergyMaterialsandSurfaceSciencesUnit(EMSS),OkinawaInstituteofScienceand Br,orCl)andmetalcations(B¼Pb,Sn)formtheBX octahedral 6 Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Okinawa, arrangement, Fig. 1a. The BX octahedra extend to a three- 6 904-0495,Japan.E-mail:[email protected] dimensionalnetworkinwhichcationsAcanbestabilizedwithin †Theseauthorscontributedequally. LuisK.Onoisastaffscientistin Matthew Leyden received his Prof. Yabing Qi's Unit (Energy Bachelor of Science in physics Materials and Surface Sciences from Cal Poly San Luis Obispo Unit) at Okinawa Institute of in 2005, and then went on to Science and Technology Grad- receivehisPh.D.inphysicsfrom uate University in Japan. He OregonStateUniversityin2011. obtained his B.S. in Physics/ He currently works as a post- Microelectronics in 2000 from doctoralscholarinProf.Yabing the University of Sa¨o Paulo, Qi'sUnitatOkinawaInstituteof Brazil. Later he joined the Science and Technology Grad- Department of Nuclear Engi- uate University researching neering in Kyoto University, perovskitesynthesisbychemical Japan, and the University of vapordeposition. Central Florida, USA, where he obtained his M.S. in 2003 and Ph.D. in 2009, respectively. His current research focuses on the fundamentalunderstandingofperovskitesolarcells. Thisjournalis©TheRoyalSocietyofChemistry2016 J.Mater.Chem.A,2016,4,6693–6713 | 6693 View Article Online JournalofMaterialsChemistryA Review thespaceformedbytheeightadjacentoctahedra(Fig.1).21The dissociateintofreecarriersinthebulk,similartoinorganicsolar larger cation A (A being larger than B) can be Cs+,22 methyl- cells, has not been completely settled.35–39 On the other hand, ammonium (CH NH +, MA+), ethylammonium (CH CH NH +, anumberofstudiessuggestthatexcitonbindingenergies(BEs) 3 3 3 2 3 EA+),15 formamidinium (NH CH]NH +, FA+),23 or mixed in perovskites are in the range of (cid:1)2–50 meV,35 and ultrafast 2 2 CH NH and 5-aminovaleric acid (5-AVA) cations [(5-AVA) (- interfacialcharge-transferdynamicstakeplace;36collectively,the 3 3 x CH3NH3)1(cid:3)x].2 The crystallographic stability and probable majorityoftheseobservations implythat perovskitesolar cells structure are estimated by considering the Goldschmidt toler- arepredominantlynon-excitonicsimilartoinorganicsolarcells ance factor and the octahedral factor.9,15,16,24 Nevertheless, the showingrelativelylowexcitonBEs,e.g.,Si(15.0meV),GaAs(4.2 e. determinationofchemicalandthermalstabilityoftheresultant meV),andCdTe,(10.5meV).37 M. enc perovskite structure requires more detailed analysis.10 CH3- In the 1990s, Mitzi and co-workers studied OHPs and 2:06:00 Aported Lic NcbeaHlnl3sdP,gbwaIap3s,otrfhe(cid:1)epo1mr.5toe5sdtetVcoo)mhanamvdeohnailgyhhiegmmhopablboilsyioteirdepstmifooanrteecrloieaeclffitrinocnieOsnH(t7P(.5dsicormelac2rt pdmaisarctaeolrlveiealr,lesdGmr¨adatezinseillryaabfnloedr pceolhe-ywcstoircorokn-ecirchseamdpeipcvlaeiclloaptpieordonpse.a4r0t–ni4e2eswAlomcflaostshstesionef 1n 6/2023 n 3.0 U rVe(cid:3)s1uslt(cid:3)in1)gainndlhonolgesca(1rr2i.e5r–6d6iffcumsi2oVn(cid:3)l1esn(cid:3)g1t)h,si.e(1.0a0mnbmipotloar1nmamtu)r.e25, pGhr¨aottzoevloltcaeilcl)teacnhdnolsooglyid,-dstyaet-esenDsSitSiCzesd (ssoslDarSScCesll)s s(DhoSwSCns oinr ed on 2/1Attributio CAdelltbhaiostueag,2nh6omtthhieexreadmtymopueentohtfyalhnaadmlirmdoeloenpoieufrominv-sclkoeairtpdeohrreaaptleioddretCeCdlaHwr3eiNtshHtia3llPnubneI3vd(cid:3)eexnr- ypFlieagrm.ov2ms.k1o4i,n4t3ei,us44minMDiyleSaaSsdaCksatirnaiin2od0d0idc9oe.4-/5wtrToibhrkreoedmrsyiedwweeares(CrteHhpelNacHresdtPbbtoyI mapeaptnhldy- nloadmons higxher charge-carrier mobility ((cid:1)33 cm2 V(cid:3)1 s(cid:3)1), resulting in CH3NH3PbBr3)perovskitesinDSSCconguratio3n13,143obt3aining wm carrierdiffusionlengthsofupto3mm.27Theoreticalstudieshave a PCE of (cid:1)3.8% and (cid:1)3.1%, respectively, using the iodine/ 5. Doe Co shown that most point defects in OHP form shallow defect triiodideredoxliquidelectrolyteasthehole-transportmaterial. 201ativ states.28–32Inaddition,grainboundarieswereshownthattheydo Duetothehighinstabilitiesoftheperovskitematerialsinthe ber Cre not generate gap states, which makes the electronic property electrolytes, ruthenium-based dyes were still the preferable Decemnder a baethhainvi-orlmofspinoglylecrcyrsytastllailn.2e8,2h9,a33liIdneaperreocvesnktitweosrikmbilyardetoQuthilaettteosf cpherooicves.kiItne2(0C1H23,NPHar3kPbaIn3)dscool-awrorckeellrssafanbdricaactheidevaeldl saoliPdC-sEtaotef 01 d u et al.,34 the existence of large spatial variations in photo- (cid:1)9.7%andmuchbetterdurability.46Thekeyadvancewasmade n se on luminescence(PL)intensityandcarrierrecombinationlifetimes possible by replacing the liquid electrolyte with a solid hole blished e is lice whiegrheerprcoobnetdraustssinwgearecoonbfsoecrvaeldPLatmthicerogscraoipne.bIonunpdaartriiceuslairn, otrfanresppoorrttsinhgalvaeyebre(eHnTpLu)bmliastheeridale,xFpiglo.r2in.4g6Stihnecedtihffeenre,natmpyerrioavd- e. Puarticl comparison to the bulk of the material within the individual skite materials, various device architectures, and fabrication s Articl This ignrateinnssitoiefsCwHer3eNHat3tPrbibIu3(cid:3)texCdlxtoptehroevsvkairtieast.i3o4nsDiiffnerreandciaetsiveinanPdL fmuentchtioodns.1o4,f47–a50sBeontshitizthere idnyewhaincdh CliHgh3tNHab3PsobrIp3tiaosnsuimndeutchees es nonradiative recombination dynamics.34 The question whether subsequentelectroninjectionintotheconductionbandofthe c Ac theperovskitesolarcellsystemisexcitonic,similartoanorganic mesoporous TiO scaffold (electron transport layer, ETL) n 2 pe solarcell,whichrequiresaheterojunctioninterfacetoseparate accompanied by hole injection from the oxidized sensitizer to O electron–hole pairs, or instead photoexcitations spontaneously the highest-occupied molecular orbital (HOMO) of the HTL. Shenghao Wang received his Yabing Qi is currently an Assis- Master's degree in Condensed tant Professor and Head of Matter Physics from Sichuan Energy Materials and Surface University, China and Doctor's Sciences Unit (EMSS) in Oki- degree in Applied Physics from nawa Institute of Science and UniversityofTsukuba,Japan,in TechnologyGraduateUniversity 2010 and 2013, respectively. (OIST). Dr Qi received his B.S., Aer that, he worked as a post- M.Phil.,andPh.D.degreesfrom doctoral researcher in Akimoto Nanjing University, Hong Kong LaboratoryinUniversityofTsu- University of Science and Tech- kuba. Currently he is a post- nology, and University of Cal- doctoralscholarinProf.Yabing ifornia Berkeley, respectively. Qi'sUnit(EnergyMaterialsand His research interests include Surface Sciences Unit) at Okinawa Institute ofScience and Tech- perovskitesolarcells,organicelectronics,surfacesciences,energy nologyGraduateUniversity(OIST).Hisresearchinterestsinclude materials and devices. Dr Qi has co-authored (cid:1)50 peer-refereed surface and interface sciences, photoemission spectroscopy tech- papers and has delivered 70+ invited and contributed research niques, organic solar cells, and organic–inorganic hybrid perov- presentationsatinternationalconferences,technicalmeetingsand skitesolarcells. universities. 6694 | J.Mater.Chem.A,2016,4,6693–6713 Thisjournalis©TheRoyalSocietyofChemistry2016 View Article Online Review JournalofMaterialsChemistryA selectivecontactscontributetotheenhancementofthecellll factor (FF). In particular, the hole selective contact tends to enhancetheopen-circuitvoltage(V )byminimizinginterfacial oc charge recombination processes, i.e. the HTL performs both functions of blocking electrons as well as transporting holes efficiently.52 Thelmmorphology,thickness,stoichiometry,crystallinityas wellasmaterialpurityhavesignicantimpactontheoverallsolar e. cell performance. A variety of solution- and vapor-based OHP M. enc deposition techniques have been reported including one-step 2:06:00 Aported Lic sssoopluivnre-ccneotavetaixcnturgau,c5m3t–i5o7ndt,ew6p1oov-ssaitpteioporn-da,4se,5sp,7io0s–ts7ei7tdihosynoblrtuiedtcihodnneipqpouroseicste,i4os1sn,5e8,–7s68,0–6821s–6o9hlvydebunraitdl–- 1n 6/2023 n 3.0 U chaesmheicvaalpovaraptoiornd,e93peotsc.itOionne,-8s2–t8e7pssepqiune-cnotiaatlinvgapisoorndeeopfotshiteiowni,d88e–l9y2 ed on 2/1Attributio ut(ihsneecdomlmmpesltephtreoedpcsoavrbeeedrcaabguyes)teheisospfmeictesiathlslioymdipnolitcheitneyhcaaansvdeealoofpwop-oclaornsmta.roHraporhcwhoeilvtoeegcry-, nloadmons ture,whichresultsindecreasedsolarcellperformance.54,94–96In wm thetwo-stepprocess,41,58,59alayerofmetalhalideisdepositedby 5. Doe Co spin-coating followed by dipping the lm into the organic salt 201ativ solutionandperovskiteformedbyachemicalreaction.However, ber Cre due to the high reaction rates of perovskite formation, it is Decemnder a rcehparlolednugciinbgiltioty.o9p7tDimesipzeitethteheprfoaccetstshinatglcaobnodraittioornysrweciothrdsueffifficciieennt- 01 d u cieshavebeenobtainedbysolutionprocessing,7,50,98itisobserved n se on that the reaction kinetics need to be rigorously controlled to e. Published article is lice vmbaaapticonhrt-abviaansriecadotinoasnpisspt.re99onaYtcadhnegvfiocarentpdheecrfood-wrempooraksniectriesonainnotdrfomdaiunpcieemrdoizvaeskCbiHtaet3cNlhaH-yteo3rI- s Articl This aFirgo.u1nd(aX) aIdneioalnscutboicfopremroBvsXk6iteocsttaruhcetdurroen.wAithcaBtiomnetfialllssatshseemspbalecde cparlolceedss,vaPpboI2r-alsmsisstwederesaonlunteioanledpirnoMceAssIva(VpAoSrPa)t.6125,603,6(cid:4)5CIinnatnheNi2r es formedbytheeightadjacentoctahedraandbalancesthechargeofthe environment for 2 h, Fig. 3a. Perovskite lms exhibited high c c wholenetwork.ReprintedwithpermissionfromMacmillianPublishers A crystallinity,uniformsurfacecoverageandlargegrainsizesupto Open Ltutdre:Nfoartu(presePuhdoot)o-ncuicbsic(reCfH.135N)H,c3oPpbyI3riwghitth(240(cid:5)144).((cid:5)b)4Osputpimerizceedll.sCtroulco-r 1micrometer,Fig.3b–d.ThehighqualitylmsofCH3NH3PbI3 coding:largedarkgray:lead;purple:iodine;brown:carbon;smalllight enabled enhanced solar cell parameters of short-circuit current gray: nitrogen; white: hydrogen atoms. Reprinted with permission (J ), V , FF, and PCE: 19.8 mA cm(cid:3)2, 0.924 V, 0.663, 12.1%, sc oc fromref.21.Copyright(2013)AmericanChemicalSociety. respectively, in a planar architecture, Fig. 3e.62,63 The surface roughnessofthelmswasmeasuredbyatomicforcemicroscopy (AFM) (5 (cid:5) 5 mm2, Fig. 3f) and calculated to be 23.2 nm. In Further charge transport of electron and hole through the arecentpublication,theauthorsstatethatitisstillunclearwhy externalcircuitcompletesthephotovoltaicoperation.8Theuse the efficiency ofperovskitesolar cellsbasedonVASP isslightly ofTiO andHTLasselectivecontactsensuresthatphotoexcited lower than that of devices derived from an optimized solution 2 chargecarriers(electronsandholes)aretransportedinopposite process.65 In this review, we focus on the different vapor-based directions. In a separate experiment, Lee et al.47 showed that methodstodepositperovskitelms,whichinmanycasesshow a mesoporous (mp-) scaffold made of Al O instead of TiO propertiesdifferentfromtheircounterpartspreparedbysolution- 2 3 2 generated a similar PCE even though Al O is an insulating basedmethods. 2 3 material. This paradigm has been rationalized by suggesting thatperovskiteitselfisagoodelectronconductor;ifso,nomp- 2. Vapor deposition by dual-source TiO scaffold is necessary at all. This led to a much simpler 2 planar-type device architecture, Fig. 2, and rst conrmed by 2.1. Vapordepositionsystemdescription Liu et al.,4 who showed efficient (PCE (cid:1) 15.4%) CH NH - Vapor deposition techniques are widely used in the semi- 3 3 PbI3(cid:3)xClx based perovskite solar cells without employing any conductor industry aiming at large scale production in opto- mesoporousmetaloxidelayer.Etgaretal.51haddemonstrated electronic applications. The viability of OHP material thatCH NH PbI couldalsoactasanefficientholeconductor, synthesis by physical vapor deposition techniques has also 3 3 3 which could even eliminate the need for employing the addi- been demonstrated.4,5,70–74,100 Such techniques offer unique tional HTL layer. However, generally both electron and hole advantagessuchas(1)itisfeasibletofabricatelmswithhigh- Thisjournalis©TheRoyalSocietyofChemistry2016 J.Mater.Chem.A,2016,4,6693–6713 | 6695 View Article Online JournalofMaterialsChemistryA Review e. M. enc 00 Ad Lic 2:06:porte 1n 3 U 2023.0 6/n 1o n 2/buti ed oAttri nloadmons tFriog.ly2teiEsvroeplulaticoendowfitthheansoolargracneilclpte-ctyhpneolhooglyecstoanrtdinugctforor.mStrtuhcetuerleacletrvoolyluteti-obnaosefdpemroevssoksitceo-pbiacseDdSSsoClaarncdelslosleidvosltvaetdef(rsos)mD(Si)SsCenwsihtiezreedtshoelaerlecce-ll 5. Dowe Com wsoitlahrncaenllodwoitthpaercoavpskpiitneg;(liai)ymeresoofppoerroouvssk(sitcea;ff(oivl)dt)hsitnruficltmurepdlasnoalrarhceetellrowjiuthncatitohninpaenrdovcsoknitteinsuooluarsclaeylel.rAodfappetreodvswkiitteh;p(ieii)rmpeisrsoiovsnkiftreo-minfirletrfa.t1e4d. 201ativ Copyright(2013)AmericanChemicalSociety. ber Cre ma ceer purity as the lms are formed by sublimating the powder In2013,Liuetal.4reportedthesynthesisofthree-dimensional ed 01 Dd un precursors aer extensive outgassing under a vacuum envi- CH3NH3PbI3(cid:3)xClx by using the dual-source vapor deposition on nse ronment; (2) in general, the initial nominal stoichiometry of techniquewithPbCl2andCH3NH3Iasprecursorsleadingtohigh blished e is lice bporetchusroslourtsio(en.ga.,nCdHva3NcuHu3mIaenvdapPobrCalt2io)ncamnebtehwodesll.cOonnttrhoelloetdhienr eMffiacliinekniceywpichzoteotvaoll.tadiecpdoesviticeedsa(PpCuEre(cid:1)C1H5.34N%H,3TPabbI3lep1e)r.oSvismkiitlaerblyy, ess Article. Pu This articl adhprriaesenscpdour,lrevspieotarPrissebdiCnnble2ydceesinosteslruaNmrt,iyNoinnt-dionmimgteaettkhhtehoeydiclnsfoo.tmoFrmoparoacemcsxiotaiuidmonentp(loteDhf,MeitthFises)odlwuilffibhmieclsniutytlhtthotaoeft utbwiysoitinAnhFgwaMniPt.hba5IvIa2enrraaoandgodedtmigCtriHeoaain3nnN,tssHhiqze3ueIaosrlfome1u(s5Rrc0sMehnsoSm)wshr.e7ood1uwTugihhnnenigfseocusrhsnmeiofmgfor5raamtniincmyillsmlmutresutafcrosatruutmriroeeands- Acc CH3NH3I:PbCl2 molar ratio is lower than 3:1.47 (3) The of the dual-source vacuum deposition process is shown in n commonly used solvents, in the solution process, can get Fig. 4.71,75 PbX (X ¼ I, Cl) and CH NH I precursor materials e 2 3 3 Op intercalated in perovskite lms. DMF, H O, and dime- contained in crucibles are heated (co-evaporation) to their cor- 2 thylsulfoxide (DMSO) were observed to form stable interme- responding sublimation temperatures. CH3NH3PbI3(cid:3)xClx and diatecomplexesofCH NH PbI $DMF,101CH NH PbI $H O,102 CH NH PbI perovskiteslayersareformedonthesubstratethat 3 3 3 3 3 3 2 3 3 3 and CH NH PbI $DMSO,103 respectively, likely to affect the isxedatadistanceof(cid:1)20cmabovethecrucibles.5Typicalbase 3 3 3 perovskite lm stability. (4) Vapor deposition techniques are pressures of 10(cid:3)5 to 10(cid:3)6 Torr are reached aer loading the suitableforthepreparationofmultilayeredstructuresofthin precursormaterials.4,5Thestoichiometry(chemicalcomposition) lms,whileitischallengingforsolutionprocessing.(5)With and lm thickness are monitored withthe aid ofpiezo-electric proper optimization, perovskite lms can be deposited by sensors4,5 mounted inside the vacuum chamber (or a quartz vapor deposition on a variety of substrates. The wettability crystalmicrobalance,QCM).Becauseperovskitesareformedby issues in solution processing oen lead to non-uniform the co-evaporation process, it requires the initial calibrationas coatingandpin-holeformation. preciseaspossibleforthethicknessesofindividualevaporated In 1997, Era et al.104 reported for the rst time the dual- PbX and CH NH I lms. Material density (r), acoustic imped- 2 3 3 source vapor deposition method to form two-dimensional ance(orZ-ratio),andgeometric(ortoolingfactor)areparameters layeredhybridleadiodideintercalatedwithanorganicammo- thatneedtobedeterminedforthecalibrationofevaporationrate niumlayer.Thesynthesisof(RNH ) PbI layeredperovskitewas ofthematerialbeingsublimated.Oenitisdifficulttondthose 32 4 performedunderapressureof(cid:1)10(cid:3)6TorrsublimatingPbI and parametersespeciallyfororganiccompounds.Forexample,Liu 2 organic ammonium iodide RNH I (2-phenylethylammonium etal.assumedthedensityandZ-ratioofCH NH Itobe1gcm(cid:3)3 3 3 3 iodide C H C H NH I was used as RNH I). The synthesis of and1,respectively,becauseitsprecisedensityisunknown.4The 6 5 2 4 3 3 KPbI under vacuum from the PbI and KI precursor sources density for CH NH Cl of 1.1 g cm(cid:3)3 was previously reported.4 3 2 3 3 wasreportedbySalau.105KPbI hasbeensuggestedasapoten- Morerecently,thedensityvalueof2.224gcm(cid:3)3forCH NH Ihas 3 3 3 tial candidate for solar cell applications because of its high beenreported.80Inaddition,thetetragonalCH NH PbI perov- 3 3 3 thermalstability(220(cid:4)C).105 skite phase was calculated to have a density of 4.149 g cm(cid:3)3.80 6696 | J.Mater.Chem.A,2016,4,6693–6713 Thisjournalis©TheRoyalSocietyofChemistry2016 View Article Online Review JournalofMaterialsChemistryA evaporation temperatureofthe PbI crucible(250–260 (cid:4)C). The 2 optimum conditions were determined by analyzing the evapo- rated perovskite lms by grazing incident X-ray diffraction (GIXRD).OncetheoptimumPbI crucibletemperature(250(cid:4)C) 2 for generating the stoichiometric perovskite is determined, perovskitelms with similar properties can beprepared repro- duciblyindicatingtherobustnessoftheprotocol.5,71 The substrate holder is maintained at near room-tempera- e. ture during perovskite deposition for the processes described M. enc above.4,5,71 Because of low-temperature processing, it is high- 2:06:00 Aported Lic ldpiregophvotiesddietiotshnidaotef-bpthyee-rsoivdteseckhictneoimqlupmeasriiossonnotofopneaxrittbhilceeuslmaurbosritpnrhatetorelesos.gtLyifuooerftttahhl.ee4 1n 6/2023 n 3.0 U dCuHa3lN-sHou3PrcbeI3v(cid:3)axcCuluxmpeervoavpskoirtaetedlmslmpsre.pFaorreedxabmytphlee,stohleuttioopn-aanndd ed on 2/1Attributio svuiandcieuf-ouvrimmew-dwseioptfhosscciarteynsdntainlllgimneeslefscehtarotouwnrefmusilolcnrcootshvceeorpasygize(eSEasncMad)leharoigefhhelxiugtnrhedtmrtehedalyst nloadmons of nanometers, Fig. 5a and b. Large-area cross-sectional SEM wm images, Fig. 5c and d, reveal that solution-processed lms 5. Doe Co exhibitlargevariationsinlmthickness(50to410nm)overthe 201ativ sample area, whilst vacuum-evaporated lms have a constant ber Cre lmthicknessof(cid:1)330nm.X-raydiffraction(XRD)patternsfor cemer a both solution- and vacuum-processed show the main diffrac- Dend tion peak positions to be identical indicating that both tech- 01 d u niques generate similar mixed-halide perovskite, Fig. 5e. The on nse Fig.3 (a)Schematicillustrationofthevapor-assistedsolutionprocess observed diffraction peaks at 14.12(cid:4), 28.44(cid:4), and 43.23(cid:4) are blished e is lice r(VeAacStPin).gPPebroI2vsfiklimteafinlmd CoHn3NthHe3IFvTaOp/ocr-TaitO1250su(cid:4)bCstrfaotre,2ohbtainineand Nby2 arhssoimgnbeidcctroysttahlest(r1u1c0t)u,re(2.4270T)h,easnmda(l3l3p0e)akpalatn1e2s.6o5f(cid:4)itshaessoigrtnheod- e. Puarticl aluttmioons,pshcearlee;b(abr)1tommp-)v;i(ecw)XSREDMpiamttaegrne;((idn)scertoimss-asgeectwioitnhalhSigEhMerimreasgoe-; tothe(110)diffractionpeakoftheremainingPbI2compound. ess Articl This Ae(effig)cwJi–eenrVecicuehsseaordafca1ts2et.r1his%eticHusnTdLoefarnCAdHMt3o1N.p5HGe3lPeilbclutI3rmobidnaeas,teirodensp.soeSlcpatirrivoec-leMyl;le(gOf)eTtnaAepDrpaitaninngdg- ATarghcehgeibtneeecsrttaustreoeslaosrfocFlaeTrlOlc/decel.llv.pi-cTaeirOabm2a/CseetHde3rNsonHof3tJPhbe,I3pV(cid:3)laxCn,FalxrF/s,hpaeinrtoedr-MoPjCueEOn:cT2tAi1oD.n5/ Acc mode AFM height images (5 (cid:5) 5 mm2) (inset: the corresponding 3D mAcm(cid:3)2,1.07V,0.67,15.4%,respectisvcelyo,cFig.5f. n topographicimage).Thecorrespondingsurfaceroughnessof23.2nm pe wasreported.Reprintedwithpermissionfromref.62.Copyright(2013) More recently, Lin et al.37 reported the use of vacuum-pro- O AmericanChemicalSociety. cessed CH NH PbI -perovskite planar structures with opti- 3 3 3 mizedultrathinn-andp-typeorganicinterlayersofPCBMand PCPDTBT, respectively, which serve to modify the electrode The densities of PbCl and PbI can be found in the literature workfunctions.Enhancedsolarcellparameterswereobtained: 2 2 withtypicalvaluesof5.85gcm(cid:3)3and6.16gcm(cid:3)3,respectively. J ¼21.9mAcm(cid:3)2,V ¼1.05V,FF¼0.72,andPCE¼16.5%. sc oc As the source-to-substrate distance generally differs from the Thecompletedevices(ITO/PEDOT:PSS/PCPDTBT/CH NH PbI / 3 3 3 source-to-QCM distance, it is oen a common practice to PCBM/LiF/Ag)hadanactiveareaof0.2cm2. perform some initial tests to determine the tooling factor. A certain amount of material is deposited on a at substrate 2.2. Large-areasolarcell recording the nominal thickness measured by the QCM with apresettoolingfactorvalue.Thisnominalthicknessvalueisthen The rst attempt for the fabrication of a larger-area solar cell compared to the thickness value determined using another (0.95 cm2) was reported by Malinkiewicz et al. in an inverted technique (e.g., AFM or surface prolometry). The linear rela- device architecture (ITO/PEDOT:PSS/polyTPD/CH NH PbI / 3 3 3 tionship provides the new tooling factor of the evaporation PCBM/3TPYMB/Au),Fig.6.Inmostreportstheactiveareasizes system.Asitwillbediscussedinmoredetailinthenextsection of the cells are smaller than 0.1 cm2, Table 1. Despite the (3.Hybriddepositionmethod),thecalibrationprocedureforthe general trend of lower FF as the active area increased, the CH NH I was reported to be difficult due to the formation of authorsobservedthatthehighV wasmaintainedandattrib- 3 3 oc anon-uniformlayerdominatedbytheVolmer–WeberorStran- uted to negligible surface and sub-bandgap trap states in ski–Krastanovgrowthmodeandthevolatilenatureoftheorganic vacuum-deposited perovskite lms.5 The industrial-scale lm.5,71,78,79AlternativelyMalinkiewiczetal.5,71kepttheevapora- manufacturing of perovskite solar cells urgently calls for tion temperature for the CH NH I crucible constant (at 70 (cid:4)C) methodsthataresuitabletocoathigh-qualityperovskitelms 3 3 and varied the CH NH I:PbI ratio by changing only the overalargearea(e.g.1cm2orlarger).15 3 3 2 Thisjournalis©TheRoyalSocietyofChemistry2016 J.Mater.Chem.A,2016,4,6693–6713 | 6697 View Article Online JournalofMaterialsChemistryA Review Table1 Summaryofperovskitesolarcellsinaplanarconfigurationwithperovskitethin-filmssynthesizedbythedifferentvapor-basedtech- niques.Perovskitethicknesses,electrodeactiveareas,solarcellparametersofshort-circuitcurrent(J ),open-circuitvoltage(V ),fillfactor(FF), sc oc andpowerconversionefficiency(PCE),andnormalizedPCEbyfilmthicknessareindicated Perovskite Electrodeactive J Norm.PCE/thickness sc Solarcellarchitecturea thickness(nm) area(cm2) (mAcm(cid:3)2) V (V) FF PCE(%) ((cid:5)%/100nm) Ref. oc FTO/c.l.-TiO2/CH3NH3PbI3(cid:3)xClx/spiro/Ag 330 0.076 21.5 1.07 0.68 15.4 4.7 4 (co-evaporation) ITO/PEDOT:PSS/polyTPD/CH NH PbI / 285 0.09 16.12 1.05 0.67–0.68 12.04 4.2 5 3 3 3 e. PCBM/Au(co-evaporation) 285 0.98 14.76 1.05 0.52 8.27 2.9 00 AM. d Licenc IPITTCOOB//MPPEE/ADDuOO(TTc::oPP-SSeSSv//apppooollryyaTTtPPioDDn//)CCHH3NNHH3PPbbII3// 228855 00..00665 1188..82 11..0097 00..6735 1142..78 54..52 7710 2:06:porte PCBM/3TPYMB/Au(co-evapor3atio3n) 3 285 0.95 17.9 1.07 0.57 10.9 3.8 1n ITO/PEDOT:PSS/PCDTBT/CH NH PbI / 370 0.2 21.9 1.05 0.72 16.5 4.5 37 3 U 3 3 3 6/202n 3.0 PFTCO60/BNMiO/L/CiFH/A3NgH(c3oP-bevI3a(cid:3)pxoCrlaxt/iPoCnB)M/Ag 250 0.07 14.2 0.786 0.65 7.26 2.9 72 ed on 2/1Attributio ((FccTooO--ee/vvCaauppSooCrraaNtt/iiCoonnH))3NH3PbI3(cid:3)xClx/PCBM/Ag 500 0.07 (cid:1)8.8 0.677 —b 3.8 0.8 72 5. Downloade Commons ICeITTvHaOOp3//NFMo6rHoa-T3OtPiCo3b/NnNI)3NP(cid:3)QBxC//sClpxH/iCr3o6N0-MH/A3egPO(bc-ITo3P/-CD6/0/BCP/Al 339200 00..00644 1168..01 11..0132 00..6668 1103..97 24..82 7743 1v (co-evaporation) ber 20Creati eITvaOp/CorHa3tiNoHn)3PbI3(cid:3)xClx/C60/Bphen/Al(co- 150 0.1 12.5 0.82 0.60 6.1 4.1 76 ma ceer FTO/PEDOT:PSS/CH3NH3PbI3(cid:3)xClx/ 400 0.12 17.3 0.97 0.63 10.5 2.6 77 Dend PCBM/Ag(co-evaporation) on 01 nsed u (FhTyOb/rcid.l.-dTeipOo2s/CitHio3nN)H3PbI3(cid:3)xClx/spiro/Ag 51035 00..0055 1170..05 11..0096 00..553656 96..93 71.23.6 78 e. Published article is lice F(F(hhTTyyOObb//rrcciidd..ll..--ddTTeeiippOOoo22ss//CCiittHHiioo33nnNN))HH33PPbbII33//ssppiirroo//AAuu 127700–300 00..0156 1(cid:1)91.892 1>.10.918 0>.05.274 1>11.248 6>.48.4 7890 ess Articl This FdFTTepOOo//CCsi67t00io//CCnHH)33NNHH33PPbbII33//ssppiirroo//AAuu((hhyybbrriidd 332200 00..0088 1188..96 11..1003 00..775747 1154..79 44..97 81 cc deposition) n A FTO/c.l.-TiO2/CH3NH3PbI3(cid:3)xClx/spiro/Au 296 0.07–0.1 19.1 0.92 0.62 10.8 3.6 82 pe (hybridCVD) O FTO/c.l.-TiO2/HC(NH2)2PbI3(cid:3)xClx/spiro/ 324 0.04–0.169 20.9 1.03 0.66 14.2 4.4 83 Au(hybridCVD) 324 1 18.4 0.97 0.43 7.7 2.4 FTO/c.l.-TiO /CH NH PbI /spiro/Ag(low- —b 0.12 21.7 0.91 0.65 12.73 — 85 2 3 3 3 pressureCVD) FTO/c.l.-TiO /CH NH PbI /spiro/Agor 320 0.12 21.0 0.952 0.61 12.2 3.8 84 2 3 3 3 Au(insitutubularCVD) ITO/PEDOT:PSS/CH3NH3PbI3(cid:3)xClx/C60/ 430 0.05 20.9 1.02 0.722 15.4 3.6 88 Bphen/Ca/Ag(sequentialdeposition) ITO/CH NH PbI /C /Ag(sequential (cid:1)350 0.09 13.6 0.8 0.5 5.4 1.5 89 3 3 3 60 deposition) FTO/c.l.-TiO /CH NH PbI /spiro/MoO/ 473 0.09 21.8 0.96 0.6 12.5 2.6 90 2 3 3 3 3 Al(sequentialdeposition) FTO/c.l.-TiO /CH NH PbI /P3HT/Au (cid:1)400 0.104 21.76 0.96 0.653 13.7 3.4 91 2 3 3 3 (sequentialdeposition) FTO/c.l.-TiO2/CH3NH3PbI3(cid:3)xClx/spiro/Au 412 0.071 22.27 1.00 0.72 16.03 3.9 92 (sequentialdeposition) 0.49 20.91 0.98 0.69 14.14 3.4 1 20.77 0.98 0.68 13.84 3.4 ITO/PEDOT:PSS/CH NH PbI /polyTPD/ 200 —b 18 1.067 0.68 12.2 6.1 93 3 3 3 PCBM/Ba/Ag(ashevaporation) aAbbreviations:FTO¼uorinedopedtinoxide;c.l.-TiO ¼compactlayeredTiO ;spiro¼2,70–7,70-tetrakis-(N,N-di-p-methoxyphenylamine)-9,90- 2 2 spirobiuorene; ITO ¼ indium tin oxide; PEDOT-PSS ¼ poly(3,4-ethylenedioxy-thiophene):poly(styrene sulfonate); polyTPD ¼ poly(N,N0-bis(4- butylphenyl)-N,N0-bis(phenyl)benzidine); PCBM ¼ (6,6)-phenyl C -butyric acid methyl ester; Bphen ¼ bathophenanthroline; NPB ¼ N,N0-di(1- 61 naphthyl)-N,N0-diphenyl-(1,10-biphenyl)-4,40-diamine; BCP ¼ bathocuproine; 3TPYMB ¼ tris(2,4,6-trimethyl-3-(pyridine-3-yl)phenyl)borane; F6- TCNNQ ¼ 2,20-(peruoronaphtalene-2,6-diylidine)dimalononitrile; spiro-MeO-TPD ¼ 2,7-bis[N,N-bis(4-methoxy-phenyl)amino]-9,9- spirobiuorene;PCDTBT¼poly(N-90-heptadecanyl-1,2,7-carbazole-alt-5,5-(40,70-di(thien-2-yl)-2010,30-benzothia-diazole)).bNotprovided. 6698 | J.Mater.Chem.A,2016,4,6693–6713 Thisjournalis©TheRoyalSocietyofChemistry2016 View Article Online Review JournalofMaterialsChemistryA 2.3. VacuumdepositionofHTL The top selective contacts (either ETL or HTL) in perovskite- based solar cells can be inuenced by the doping and envi- ronmental conditions (air, humidity, temperature, and light- soaking) inwhichthe cellisbeingoperated.106–109Effortshave beenmadetondETL/HTLmaterialsthat arelessinuenced by environmental conditions, which is expected to help mini- mize batch-to-batch variations.70,72–74 For example, Momblona e. et al.70 fabricated the inverted structure solar cell (ITO/ M. enc 00 Ad Lic 2:06:porte 1n 3 U 2023.0 6/n 1o n 2/buti ed oAttri nloadmons wm 5. Doe Co 1v 20ati ber Cre ma ceer Dend Fig.4 Illustrationofthedual-sourcevacuumdepositioninstrument. 01 d u The PbX2 (X ¼ I, Cl) and CH3NH3I (MAI) precursors are thermally on nse evaporatedinvacuum.Thedepositionrateandthicknessaremoni- Fig.6 J–VcurvesfortheoptimizedCH3NH3PbI3perovskitelayerwith blished e is lice troefr.e7d5u.singquartzmicrobalances.Reproducedwithpermissionfrom asPoEslDmarOaclTle:(PlAlSi¼nS/Pp0lo.a0lny6aT5rPcDhme/Ct2e)HraonNjudHnlcaPtrigboeInr/a(PArCc¼BhiMt0e./c93t5TuPcreYmMi2sB)ce/oAlemuc.tprooRsdeeedpsribozydeu.ITTcOhede/ e. Puarticl withpermissionfromref.371.3 3 s Articl This s e c c A n e p O Fig.5 (a)SEMtop-viewofvacuum-depositedCH3NH3PbI3(cid:3)xClxperovskitefilm.(b)Cross-sectionalSEMimageunderhighmagnificationofthe completecellfabricatedfromvacuum-depositedperovskitefilm.(candd)Cross-sectionalSEMimagesunderlowermagnificationcomparing the(c)vacuum-and(d)solution-processedperovskitefilms.(e)XRDspectraofvacuum-andsolution-processedperovskitefilms.J–Vcurvesof the best performing vacuum- and solution-processed planar heterojunction perovskite solar cells measured under AM1.5 (101 mW cm(cid:3)2) irradianceandinthedark.ReprintedwithpermissionfromMacmillanPublishersLtd:Nature(ref.4),copyright(2013). Thisjournalis©TheRoyalSocietyofChemistry2016 J.Mater.Chem.A,2016,4,6693–6713 | 6699 View Article Online JournalofMaterialsChemistryA Review PEDOT:PSS/polyTPD/CH NH PbI /PCBM/Au) by varying the calibrating the QCM parameters for CH NH I materials were 3 3 3 3 3 perovskite layer thicknesses from 200 nm to 900 nm. J was mentionedinalmost allofthese studiesasa keychallenge to sc observedtoincreaseastheperovskitelayerthicknessincreased, achieve reproducible, uniform and stoichiometry controllable andtherateofJ increasewasfasteratthebeginningupto300 perovskite lms.5,37,71,74,75 The evaporation rate of CH NH I is sc 3 3 nmandslowerfordeviceswiththickeractivelayers.Thedevices difficult to calibrate and control because of its relatively high with thicker perovskite layers were observed to have lower FF vapor pressure. In addition, CH NH I is observed to deposit 3 3 reducingtheoverallPCE.Thecellwitha900nmperovskitelm everywhere on the cold surfaces inside the chamber. For thicknesswasstillabletogeneraterespectablesolarparameters instance,theCH NH Ilayerwasdetected(XRDandAFM)onthe 3 3 e. of Jsc, Voc, FF, and PCE: 19.8 mA cm(cid:3)2, 0.92 V, 0.4, 7.2%, topsurfaceofasubstratethatisfacingtheoppositedirectionof M. enc respectively. Interestingly, the authors observed that replacing theCH3NH3Isource.79Incontrast,leadhalideswereobservedto 00 Ad Lic thepristinepolyTPDwithaslightlyp-dopedversionofpolyTPD depositmainlyalongtheline-of-sightdirectionfromthesource. 12:06:nporte (t0h.e05s%ignoixicdaiznetdi)minprtohveecmelelnwtiothfath9e00FFnmanpdeProCvEsk(iJtsecl¼ay1e9r.l5edmtAo TtohethheigrheavdaipnogropfrethsseuQreCoMfCthHa3tNiHs3uIsaeldsotoleamdosntiotocrrothsse-teavlkaipnog- 6/2023 n 3.0 U cshmo(cid:3)w2e,dVothca¼tw0i.t9h4aVn,aFpFpr¼op0r.i6a5te, HanTdL,PsCoElar¼ce1l2l%PC).EsThhiasdwoonrlky rwaotiroknerrsatdeeoveflloepaeddhaalindeews.mToetshoolvdeoslougcyh(athcehahlylebnrgide,dQeipaonsditicoon- ed on 2/1Attributio atfioowrnee,aleiktctddroeempnesonandnsedtnrachteoedloensthitnehevparpcoeuprueomrvtsi-kepsirtoeocfellsomsnedgthpdiceiffkronuvessiskosin.teIlnenlamgdtdsh.is- mcvaoecntuthruoomdll)inchwgahmtehrbeeerCt.h7H8e,739NpTHehr3oeIvosvkpaitptieomrisztpeoadircthhiaioolmmpeer-tbersuysiulitrseinesinntsrsuuimdreeedntthbaey- nloadmons Perovskitesolarcellsusinginorganicholeconductors(such tion is illustrated in Fig. 7a.78 A more detailed study on the wm as NiO, CuI, and CuSCN) as HTLs have received attention hybriddepositionmethodwasreportedbyWangetal.79andis 5. Doe Co because of their better stability than HTLs using spiro-MeO- discussedlaterinthissection.Themainvacuumchamber(Part 201ativ TAD.72,110,111 Subbiah et al.72 reported the initial attempts of #1inFig.7a)isevacuatedbyusingapumpingsystemconsisting ber Cre vacuum-depositedCH3NH3PbI3(cid:3)xClxperovskiteemployingNiO ofaturbomolecularpump(HiPace300,Pfeiffer)andamanual cemer a and CuSCN, Table 1. Although the reported PCEs were much gate-valve (10840-CE01, VAT). The substrate holder stage (Part Dend lowercomparedtothoseemployingorganicHTLs,itrepresents #3)allowsstablecoolingandheatinginthetemperaturerange 01 d u apromisingsteptowardstability. from(cid:3)190(cid:4)Cupto200(cid:4)Candcanaccommodateawiderange on nse Schulzetal.112identiedthatV lossesofupto0.4eVcould ofsubstrate(Part#4)sizesupto5(cid:5)5cm2.Asubstrateshutter e. Published article is lice aM¼ries5Oe.T4frAoeDmVH).aTnPLoio(lIanEnizd¼aetr5io.0neteeVna)le.a7r4gnydr(eICpEHoo)rcm3tNeidHsm3fPuabtllcIy3h(cid:3)vbxaCectluwxupemeenr-optvhrsoekcisetpessi(reIoEd- (rQPaCateMrst#(aP5rae)rimts#mo6n)oifutaoncritenedgddbjuyoswttwnbowealQordwCMmthsoen(Psituaobrrtsssttr#ha6etePa.nbTCdhle2#7ee)vv.aaTpphoorreaattiiroosnnt s Articl This uplsainngarvahreioteursopju-dnocptieodnHCTHLs3NwHit3hPdbiIff3(cid:3)erxCenlxtIpEevraolvuseksitreansgoilnagrfcreolmls rmatoeniwtohriltehtehCeHse3NcoHn3dIvQaCpMor(aPnadrta#v7o)idfsactihnegcuropswsa-tradlkisfruosmedthtoe es 5.0 eV to 5.6 eV and C as the ETL. The authors studied the metalhalidesource.Twoevaporationsourcesareusedforthe c 60 Ac inuences of the energy level mismatch between the valence sublimation of the precursor materials. CH NH I vapor was Open bandmaximum(VBM)ofCH3NH3PbI3(cid:3)xClx(IE¼5.4eV)perov- produced by a Knudsen cell (Part #8) type s3ourc3e to ll the skiteandthedifferentHTLsonthesolarcellperformance.Ithas chamber.Itisemphasizedthatapermanentshutterinfrontof beenshownthattheIEoftheHTLcorrelateswiththeV ofsolar the Knudsen cell was mounted for avoiding the high ux of oc cell devices. Devices employing HTLs with IEs of up to 5.3 eV CH NH Ireachingdirectlythesubstrate,whichmaycausethe 3 3 yieldedahighV andPCE.Incontrast,withIEsbeyond5.3eV, non-uniformcompositionofthelm.Toachieveahighlevelof oc asubstantialdecreaseinbothJ andV wasobserved,whichwas lm uniformity in thickness and composition as well as to sc oc attributed to the absence of driving force for hole extraction. providelargescaleuniformevaporation(5(cid:5)5cm2),thePbCl 2 Optimizedsolarcellsemployingspiro-MeO-TPDinaplanarcell isresistivelyheatedfromalargedish-shapedcrucible(Part#9) conguration of ITO/F6-TCNNQ/spiro-MeO-TPD/CH3NH3PbI3(cid:3)x- with(cid:1)3cmindiameter.Theheatingelement(Part#10)consists Cl/C /AggeneratedJ ¼16mAcm(cid:3)2,V ¼1.03V,FF¼0.66, ofatungstenwire(f¼0.25mm)woundintoaspiralshapeand x 60 sc oc and PCE ¼ 10.9%. In another study of fully vacuum-processed connectedtoapowersupplythroughelectricfeedthroughs(Part planarheterojunctionperformedbyKimetal.,73theemployment #11). The halide shutter (Part #12) allows de-convolution and of HTL (MoO /NPB) and ETL (C /BCP) with a double-layer extrapolation of the lead halide evaporation rate aer sub- 3 60 structurewasobservedtoshowimprovedenergylevelalignments tractingtheCH NH IevaporationrateenteringintherstQCM 3 3 at the interfacial contact resulting in higher V . The solar cell (Part#6).Thetotalpressureinsidethechamberismonitoredby oc with ITO/MoO /NPB/CH NH PbI /C /BCP/Al planar hetero- usingafull-range((cid:1)105to10(cid:3)7Pa)pressuregauge(Part#13). 3 3 3 3 60 junctionarchitectureshowedbestsolarcellparametersofJ ¼ TheinitialCH NH Icalibrationandthedeterminationofthe sc 3 3 18.1mAcm(cid:3)2,V ¼1.12V,FF¼0.68,andPCE¼13.7%. optimized CH NH I:PbCl ratio procedure are similar to the oc 3 3 2 method described by Malinkiewicz et al. (see Section 2).5,71 3. Hybrid deposition method However,inthehybriddeposition,becausetheCH NH IQCM 3 3 faces upwards, the QCM parameters are set to values in such Despite the aforementioned advantages of vacuum-based a way that the signal-to-noise ratio was reasonable to monitor fabrication of perovskite layers and solar cells, difficulties in the CH NH I during evaporation. The optimized parameters 3 3 6700 | J.Mater.Chem.A,2016,4,6693–6713 Thisjournalis©TheRoyalSocietyofChemistry2016 View Article Online Review JournalofMaterialsChemistryA e. M. enc 00 Ad Lic 2:06:porte 1n 3 U 2023.0 6/n 1o n 2/buti ed oAttri nloadmons wm 5. Doe Co 1v 20ati ber Cre ma ceer ed Dn 01 d u n se on blished e is lice e. Puarticl s Articl This s e c Ac Fig.7 (a)Sideviewofthehybriddepositionmethodsystem:(1)mainvacuumchamber;(2)pumpingsystemcomprisingagate-valveandaturbo n molecularpump;(3)substrateholderstagewhichallowscoolingandheatingfrom(cid:3)190(cid:4)Cto200(cid:4)C;(4)substratesizesofupto5(cid:5)5cm2;(5) e Op substrateshutter;(6)QCMfacingdownwards;(7)QCMfacingupwards;(8)KnudsencellevaporatorforproducingMAIvaporpartialpressure;(9) widelyopeneddish-shapedcruciblefortheevaporationofleadhalidecompounds;(10)spiral-shapedtungstenwire;(11)electricfeedthroughs; (12)leadhalideshutter;(13)pressuregauge.(b)XRDandpictureoftheperovskitefilmpreparedinthehybriddepositionsystemonalarge(5(cid:5)5 cm2)ITO/glasssubstrateandmeasuredat12differentpoints.Notethattheas-preparedfilmsshowalightorangecolor.Thedarkbrowncolorin thepictureisfromthecoppersampleholder.(b)XRDandpictureoftheperovskitefilmpreparedinthehybriddepositionsystemonalarge(5(cid:5)5 cm2)ITO/glasssubstrateandmeasuredat12differentpoints.(c)AFMtopographyimage(scansize:20mm(cid:5)20mm)oftheperovskitefilm((cid:1)50 nm)depositedontheITOsubstratefromwhichthesurfaceRMSroughnessof(cid:1)4.6nmwasextracted.(d)J–Vcharacteristicsofthesolarcells basedontheperovskitefilmswithtwodifferentthicknessespreparedbythehybriddepositionmethodunderAM1.5Gillumination.Solarenergy- to-electricityconversionsof6.3%(bluecurve)and9.9%(redcurve)wereextractedfordevicesusing(cid:1)50nmand(cid:1)135nmperovskitefilms, respectively.Reproducedfromref.78withpermissionofTheRoyalSocietyofChemistry. werer¼0.2gcm(cid:3)3,Z-factor¼0.2,andtoolingfactor¼100.The a uniform semi-transparent light-orange color with a highly absolute amount of CH NH I inside the chamber cannot be reective(shiny)surface,distinctivelydifferentfromtheblackor 3 3 quantied. Therefore, the perovskite deposition conditions darkbrownishcolorcommonlyobservedforsolutionprocessed (PbCl :CH NH I ratio) were optimized by depositing several samples. Based on AFM measurements the surface roughness 2 3 3 batchesofperovskitelmswithvariedCH NH Inominalrates valuesof(cid:1)4.6nm(Fig.7c)and(cid:1)9nmweredeterminedforthe 3 3 to identify the evaporation conditions that led to strong XRD (cid:1)50nmand(cid:1)135nmperovskitelms,respectively. peaks measured on perovskite lms. In this way, large-area Thecentimeter-scaleuniformsemi-transparentnatureofthe uniformityoftheperovskitelms((cid:1)135nm)wasdemonstrated perovskite lms grown by the hybrid deposition method is bymeasuringXRDpatternsat12differentpointsonthe5(cid:5)5 particularly suitableforlarge-scale windowphotovoltaic appli- cm2depositedlm,Fig.7b.Thehybrid-depositedlmswith(cid:1)50 cationswheregoodtransparencyandreasonableefficiencyare nm and (cid:1)135 nm perovskite lms were observed to show prerequisites.113,114Thebestperformingdeviceforthe(cid:1)50nm Thisjournalis©TheRoyalSocietyofChemistry2016 J.Mater.Chem.A,2016,4,6693–6713 | 6701