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Kusashanda zvakanaka kwemasero ezuva e lead triiodide perovskite kwave kuchishandiswa zvakanyanya kuvandudza mashandiro emasero ezuva e lead triiodide perovskite, asi mhedzisiro yezvikanganiso zvakasiyana-siyana pakugara kwe α-phase haisati yanyatsojeka; Pano, tichishandisa dzidziso ye density functional, tinoona kekutanga nzira yekuora kwe formamidine lead triiodide perovskite kubva pa α-phase kuenda ku δ-phase uye tinodzidza mhedzisiro yezvikanganiso zvakasiyana-siyana pachikamu chekuchinja simba. Mhedzisiro yekufananidzira inofanotaura kuti nzvimbo dzisina iodine dzinogona kukonzera kuora nekuti dzinoderedza zvakanyanya chivharo chesimba chekuchinja kwe α-δ phase uye dzine simba rakaderera rekugadzira pamusoro pe perovskite. Kuunzwa kwe dense layer ye lead oxalate isinganyunguduke mumvura pamusoro pe perovskite kunodzivirira zvakanyanya kuora kwe α-phase, kudzivirira kufamba uye volatilization ye iodine. Pamusoro pezvo, nzira iyi inoderedza zvakanyanya interfacial nonradiative recombination uye inowedzera kushanda kwemasero ezuva kusvika 25.39% (yakasimbiswa 24.92%). Mudziyo usina kuvhurwa unokwanisa kuramba uchishanda zvakanaka ne92% mushure mekushanda nesimba guru kwemaawa 550 uchishandisa 1.5 G air mass irradiation.
Kushanda nesimba kwekushandura simba (PCE) kwemaseru ezuva eperovskite (PSCs) kwasvika pa26%1. Kubva muna 2015, maPSC emazuva ano akasarudza formamidine triiodide perovskite (FAPbI3) sechikamu chinotora chiedza nekuda kwekugadzikana kwayo kwakanaka kwekupisa uye bandgap inodiwa iri pedyo nemuganho weShockley-Keisser we2,3,4. Zvinosuwisa kuti mafirimu eFAPbI3 anochinja kubva pachikamu cheblack α kuenda pachikamu cheyero chisiri perovskite δ patembiricha yemumba5,6. Kudzivirira kuumbwa kwechikamu chedelta, macomposition akasiyana-siyana akaomarara eperovskite akagadzirwa. Nzira yakajairika yekukunda dambudziko iri ndeyekusanganisa FAPbI3 nemusanganiswa wemethyl ammonium (MA+), cesium (Cs+) uye bromide (Br-) ions7,8,9. Zvisinei, mahybrid perovskites anotambura nekuwedzera kwebandgap uye kupatsanurwa kwechikamu chinokonzerwa ne photoinduced, izvo zvinokanganisa mashandiro uye kugadzikana kwekushanda kwePSCs10,11,12 inobuda.
Ongororo dzichangobva kuitwa dzakaratidza kuti FAPbI3 yakachena isina doping ine kugadzikana kwakanaka nekuda kwehunhu hwayo hwakanaka uye zvikanganiso zvishoma13,14. Nokudaro, kuderedza zvikanganiso nekuwedzera hunhu hwehunhu hweFAPbI3 inzira yakakosha yekuwana PSCs2,15 inoshanda uye yakagadzikana. Zvisinei, panguva yekushanda kweFAPbI3 PSC, kuora kusvika pachikamu cheyero chehexagonal chisina perovskite δ chisingadiwe kunogona kuitika16. Maitiro acho anowanzo tanga panzvimbo nemiganhu yezviyo zvinokurumidza kubatwa nemvura, kupisa nechiedza nekuda kwekuvapo kwenzvimbo dzakawanda dzisina kunaka17. Nokudaro, kusvetuka pamusoro/zviyo kwakakosha kuti kugadzikise chikamu chitema cheFAPbI318. Nzira dzakawanda dzekudzivirira hunhu, kusanganisira kuunzwa kweperovskites dzakaderera, mamorekuru eLewis ane acid-base, uye ammonium halide salts, dzakafambira mberi zvikuru mu formamidine PSCs19,20,21,22. Kusvika pari zvino, zvidzidzo zvakawanda zvakatarisana nebasa rezvikanganiso zvakasiyana-siyana mukuona hunhu hwe optoelectronic hwakadai se carrier recombination, diffusion length uye band structure mu solar cells22,23,24. Semuenzaniso, density functional theory (DFT) inoshandiswa kufanotaura simba rekuumbwa uye mazinga esimba ekubata ezvikanganiso zvakasiyana-siyana, izvo zvinoshandiswa zvakanyanya kutungamira dhizaini yepassivation20,25,26. Sezvo huwandu hwezvikanganiso huchiderera, kugadzikana kwechishandiso kunowanzovandudzika. Zvisinei, mu formamidine PSCs, mashandiro epesvedzero yezvikanganiso zvakasiyana-siyana pakugadzikana kwechikamu uye hunhu hwe photoelectric anofanirwa kusiyana zvachose. Sekuziva kwedu, kunzwisisa kwakakosha kwekuti zvikanganiso zvinokonzeresa sei cubic kuenda ku hexagonal (α-δ) phase transition uye basa repassivation pamusoro pekugadzikana kwechikamu che α-FAPbI3 perovskite harisati ranzwisiswa zvakanaka.
Pano, tinoratidza nzira yekuora kweFAPbI3 perovskite kubva pa α-phase nhema kuenda ku δ-phase yero uye pesvedzero yezvikanganiso zvakasiyana-siyana pakudzivirira simba kwekuchinja kwe α-to-δ-phase kuburikidza neDFT. Nzvimbo dzisina chinhu dzeI, dzinogadzirwa zviri nyore panguva yekugadzira mafirimu nekushanda kwemudziyo, dzinofungidzirwa kuti ndidzo dzinogona kutanga shanduko ye α-δ phase. Nokudaro, takaunza denderedzwa re lead oxalate (PbC2O4) risinganyungudike mumvura uye rakagadzikana nemakemikari pamusoro peFAPbI3 kuburikidza nekuita kwe in situ. Lead oxalate surface (LOS) inodzivirira kuumbwa kwenzvimbo dzisina chinhu dzeI uye inodzivirira kufamba kwemaI ions kana ichikurudzirwa nekupisa, chiedza, uye magetsi. LOS inoguma yaderedza zvakanyanya interfacial nonradiative recombination uye inovandudza kushanda kweFAPbI3 PSC kusvika 25.39% (yakasimbiswa kusvika 24.92%). Mudziyo weLOS usina kuvhurwa wakachengetedza 92% yekushanda kwawo kwekutanga mushure mekushanda papower point (MPP) kwemaawa anopfuura 550 pamhepo inofananidzwa (AM) ye1.5 G yemwaranzi.
Takatanga taita maverengero e ab initio kuti tiwane nzira yekuparadzana kweFAPbI3 perovskite kuenda kuchinjo kubva pachikamu cheα kuenda kuchikamu cheδ. Kuburikidza nemaitiro ekushandura chikamu akadzama, zvakaonekwa kuti shanduko kubva pachikamu chemakona chetatu-dimensional [PbI6] octahedron muchikamu checubic α cheFAPbI3 kuenda kuchikamu che one-dimensional edge-sharing [PbI6] octahedron muchikamu che hexagonal δ cheFAPbI3 inowanikwa. kutyora 9. Pb-I inogadzira chisungo mudanho rekutanga (Int-1), uye chidziviriro chayo chesimba chinosvika 0.62 eV/cell, sezvakaratidzwa muMufananidzo 1a. Kana chikamu che octahedron chachinjirwa munzira ye [0\(\bar{1}\)1], cheni pfupi ye hexagonal inowedzera kubva pa 1×1 kuenda pa 1×3, 1×4 uye pakupedzisira inopinda muchikamu che δ. Chiyero chekutungamira kwenzira yese i (011)α//(001)δ + [100]α//[100]δ. Kubva padhayagiramu yekugovera simba, zvinogona kuwanikwa kuti mushure mekuumbwa kwechikamu cheδ cheFAPbI3 muzvikamu zvinotevera, chivharo chesimba chakaderera pane chekuchinja kwechikamu cheα, zvinoreva kuti kuchinja kwechikamu kuchakurumidziswa. Zviri pachena kuti danho rekutanga rekudzora kuchinja kwechikamu rakakosha kana tichida kudzvinyirira kuora kwechikamu cheα.
Maitiro ekushandura chikamu kubva kuruboshwe kuenda kurudyi - chikamu chenhema cheFAPbI3 (α-phase), chikamu chekutanga chePb-I bond (Int-1) uye chikamu chePb-I bond (Int-2, Int -3 uye Int -4) uye chikamu chechiyero cheFAPbI3 (chikamu chedelta). b Zvipingamupinyi zvesimba kuchinjiko cheα kuenda kuδ chikamu cheFAPbI3 zvichibva pane zvakasiyana-siyana zvemukati zvepfungwa. Mutsetse une madotsi unoratidza chipingamupinyi chesimba chekristaro yakanaka (0.62 eV). c Simba rekuumbwa kwezvikanganiso zvepfungwa huru pamusoro peperovskite yelead. Abscissa axis isimbi chipingamupinyi chechinjiko cheα-δ chikamu, uye axis yekurongeka isimba rekuumbwa kwezvikanganiso. Zvikamu zvakafukidzwa negrey, yero negirini imhando I (yakaderera EB-high FE), mhando II (yakakwira FE) uye mhando III (yakaderera EB-low FE), zvichiteerana. d Simba rekuumbwa kwezvikanganiso VI uye LOS yeFAPbI3 mukutonga. e I chipingamupinyi chekutama kwemaion mukutonga uye LOS yeFAPbI3. f – kuratidzwa kwechimiro chekutama kwemaion eI (mabhora eorenji) uye gLOS FAPbI3 (grey, lead; violet (orenji), iodine (mobile iodine)) mukutonga kwegf (kuruboshwe: maonero epamusoro; kurudyi: chikamu chakachinjika, brown); kabhoni; bhuruu rakachenuruka – nitrogen; tsvuku – okisijeni; pink rakachenuruka – hydrogen). Data rekwakabva rinopihwa muchimiro chemafaira edata rekwakabva.
Takabva tadzidza zvakarongeka nezvesimba rema "intrinsic point defects" akasiyana-siyana (kusanganisira PbFA, IFA, PbI, uye IPb antisite occupancy; ma "atomu" ePbi neIi interstitial; uye VI, VFA, uye VPb vacancies), ayo anoonekwa sezvinhu zvikuru. zvinokonzera kuora kwechikamu cheatomu ne "energy level" zvinoratidzwa muMufananidzo 1b neSupplementary Table 1. Zvinofadza kuti, hazvisi zvese zvinokanganisa zvinoderedza "energy barrier" yekuchinja kwechikamu cheα-δ (Mufananidzo 1b). Tinotenda kuti zvikanganiso zvine "low formation energy" uye "low α-δ phase transition energy barriers" zvinoonekwa sezvinokanganisa "phase stability". Sezvakambotaurwa, nzvimbo dzine "lead-rich" dzinoonekwa sedzinoshanda kune formamidine PSC27. Saka, tinotarisa pane "PbI2-terminated (100) surface" pasi pe "lead-rich". "Defect formation energy" ye "surface intrinsic point defects" inoratidzwa muMufananidzo 1c neSupplementary Table 1. Zvichibva pa "energy barrier" (EB) uye "phase transition formation energy" (FE), zvikanganiso izvi zvakakamurwa kuita mhando nhatu. Rudzi I (low EB-high FE): Kunyangwe IPb, VFA neVPb zvichideredza zvakanyanya chidziviriro chesimba kukuchinja kwechikamu, zvine simba rekugadzira rakawanda. Saka, tinotenda kuti mhando idzi dzezvikanganiso dzine mhedzisiro shoma pakuchinja kwechikamu sezvo zvisingawanzo kuumbwa. Rudzi II (high EB): Nekuda kwekuvandudzwa kwe α-δ phase transition energy barrier, zvisizvo zve anti-site PbI, IFA nePbFA hazvikuvadzi kugadzikana kwechikamu che α-FAPbI3 perovskite. Rudzi III (low EB-low FE): zvisizvo zveVI, Ii nePbi zvine simba rekugadzira rakaderera zvinogona kukonzera kuora kwechikamu chedema. Kunyanya tichifunga nezve FE neEB VI yakaderera, tinotenda kuti nzira inoshanda zvikuru ndeyekuderedza nzvimbo dzeI.
Kuti tideredze VI, takagadzira dense layer yePbC2O4 kuti tivandudze pamusoro peFAPbI3. Zvichienzaniswa neorganic halide salt passivators dzakadai sephenylethylammonium iodide (PEAI) uye n-octylammonium iodide (OAI), PbC2O4, iyo isina mobile halogen ions, inogara yakagadzikana nemakemikari, hainyungudike mumvura, uye inodzima nyore nyore kana yamutswa. Kugadzikana kwakanaka kwehunyoro hwepamusoro uye simba remagetsi reperovskite. Kunyungudika kwePbC2O4 mumvura i0.00065 g/L chete, iyo yakaderera kupfuura yePbSO428. Chinonyanya kukosha ndechekuti dense uye uniform layers dzeLOS dzinogona kugadzirwa zvinyoro nyoro pamafirimu eperovskite tichishandisa in situ reactions (ona pazasi). Takaita DFT simulations ye interfacial bonding pakati peFAPbI3 nePbC2O4 sezvakaratidzwa muSupplementary Figure 1. Supplementary Table 2 inoratidza defect formation energy mushure mekuiswa kweLOS. Takawana kuti LOS haingowedzeri simba rekuumbwa kweVI defects ne 0.69–1.53 eV (Mufananidzo 1d), asiwo inowedzera simba rekuitwa kweI panzvimbo yekutama uye yekubuda (Mufananidzo 1e). Muchikamu chekutanga, I ions dzinofamba pamwe chete neperovskite surface, zvichisiya VI ions munzvimbo ye lattice ine energy barrier ye 0.61 eV. Mushure mekuunzwa kweLOS, nekuda kwemhedzisiro yekuvharirwa kwesteric, activation energy yekutama kweI ions inowedzera kusvika ku. 1.28 eV. Munguva yekutama kweI ions dzichibva panzvimbo yeperovskite, energy barrier muVOC yakakwirawo kupfuura iri mu control sample (Mufananidzo 1e). Schematic diagrams dzeI ion migration pathways in control uye LOS FAPbI3 dzinoratidzwa muMufananidzo 1 f na g, zvichiteerana. Mhedzisiro yekutevedzera inoratidza kuti LOS inogona kudzivirira kuumbwa kweVI defects uye volatilization yeI, nokudaro ichidzivirira nucleation ye α kuenda ku δ phase transition.
Kusangana pakati peoxalic acid neFAPbI3 perovskite kwakaedzwa. Mushure mekusanganisa mhinduro dzeoxalic acid neFAPbI3, huwandu hwakawanda hwemvura yakachena hwakaumbwa, sezvakaratidzwa muMufananidzo Wekuwedzera 2. Chigadzirwa cheupfu chakaonekwa sechinhu chePbC2O4 chakachena uchishandisa X-ray diffraction (XRD) (Mufananidzo Wekuwedzera 3) uye Fourier transform infrared spectroscopy (FTIR) (Mufananidzo Wekuwedzera 4). Takaona kuti oxalic acid inonyungudika zvakanyanya muisopropyl alcohol (IPA) patembiricha yemukamuri ine solubility yeinenge 18 mg/mL, sezvakaratidzwa muMufananidzo Wekuwedzera 5. Izvi zvinoita kuti kugadziriswa kunotevera kuve nyore sezvo IPA, se common passivation solvent, isingakuvadzi perovskite layer kupfuura nguva pfupi29. Saka, nekunyudza firimu reperovskite mumushonga weoxalic acid kana kutenderedza mhinduro yeoxalic acid paperovskite, PbC2O4 yakatetepa uye yakakora inogona kuwanikwa nekukurumidza pamusoro pefirimu reperovskite zvichienderana ne equation yemakemikari inotevera: H2C2O4 + FAPbI3 = PbC2O4 + FAI +HI. FAI inogona kunyungudutswa muIPA nokudaro yobviswa panguva yekubika. Ukobvu hweLOS hunogona kudzorwa nenguva yekuita uye huwandu hwepakutanga.
Mifananidzo ye scanning electron microscopy (SEM) ye control uye LOS perovskite films inoratidzwa muMifananidzo 2a,b. Mhedzisiro yacho inoratidza kuti perovskite surface morphology yakachengetedzwa zvakanaka, uye huwandu hwakawanda hwezvidimbu zvidiki zvakaiswa pamusoro pe grain surface, iyo inofanirwa kumiririra PbC2O4 layer yakagadzirwa ne in-situ reaction. Firimu reLOS perovskite rine surface yakapfava zvishoma (Supplementary Picture 6) uye angle yakakura yekubatana nemvura kana tichienzanisa ne control film (Supplementary Picture 7). High-resolution transverse transmission electron microscopy (HR-TEM) yakashandiswa kusiyanisa surface layer yechigadzirwa. Zvichienzaniswa ne control film (Fig. 2c), yunifomu uye dense thin layer ine ukobvu hweinenge 10 nm inoonekwa zvakajeka pamusoro peLOS perovskite (Fig. 2d). Uchishandisa high-angle annular dark-field scanning electron microscopy (HAADF-STEM) kuongorora kubatana kuri pakati pePbC2O4 neFAPbI3, kuvapo kwenzvimbo dzecrystalline dzeFAPbI3 nenzvimbo dzisina chimiro dzePbC2O4 kunogona kuonekwa zvakajeka (Mufananidzo Wekuwedzera 8). Kuumbwa kwepamusoro pe perovskite mushure mekurapwa kweoxalic acid kwakaratidzwa nekuyera kweX-ray photoelectron spectroscopy (XPS), sezvakaratidzwa muMifananidzo 2e–g. MuMufananidzo 2e, C 1s peaks dzinenge 284.8 eV uye 288.5 eV ndedzezviratidzo zveCC neFA, zvichiteerana. Zvichienzaniswa ne membrane yekudzora, membrane yeLOS yakaratidza peak yakawedzerwa pa289.2 eV, inokonzerwa neC2O42-. O 1s spectrum yeLOS perovskite inoratidza peak nhatu dzakasiyana dzeO 1s pa531.7 eV, 532.5 eV, uye 533.4 eV, zvinoenderana neCOO yakabviswa protonated, C=O yemaatomu eOxalate asina kusimba 30 neO echikamu cheOH (Mufananidzo 2e). )). Kune muenzaniso wekudzora, peak diki yeO 1s chete ndiyo yakaonekwa, iyo inogona kuverengerwa neoxygen chemisorbed pamusoro. Hunhu hwe membrane yekudzora yePb 4f7/2 nePb 4f5/2 huri pa138.4 eV uye 143.3 eV, zvichiteerana. Takaona kuti LOS perovskite inoratidza kuchinja kwePb peak yeinenge 0.15 eV kuenda kune simba rakakwirira rekusunga, zvichiratidza kudyidzana kwakasimba pakati pemaatomu eC2O42- nePb (Mufananidzo 2g).
a Mifananidzo yeSEM ​​yekutonga uye b mafirimu eLOS perovskite, maonero epamusoro. c High-resolution cross-sectional transmission electron microscopy (HR-TEM) yekutonga uye d mafirimu eLOS perovskite. XPS yepamusoro ye e C 1s, f O 1s uye g Pb 4f mafirimu eperovskite. Data resource rinopihwa muchimiro chemafaira edata resource.
Zvichienderana nemhedzisiro yeDFT, zvinofungidzirwa kuti VI defects uye I migration zvinokonzeresa nyore nyore kuchinja kwechikamu kubva kuα kuenda kuδ. Mishumo yapfuura yakaratidza kuti I2 inoburitswa nekukurumidza kubva kumafirimu eperovskite akavakirwa paPC panguva yekunyudzwa kwechiedza nekupisa mushure mekuisa mafirimu kuchiedza nekupisa31,32,33. Kuti tisimbise mhedzisiro yekugadzikana kwelead oxalate paα-phase yeperovskite, takanyudza mafirimu econtrol neLOS perovskite mumabhodhoro egirazi anoonekera ane toluene, zvichiteerana, uye takaaisa nechiedza chezuva chimwe chete kwemaawa makumi maviri nemana. Takayera kunyudzwa kweultraviolet nechiedza chinoonekwa (UV-Vis). ) toluene solution, sezvakaratidzwa muMufananidzo 3a. Zvichienzaniswa nemuenzaniso wecontrol, kudzika kwakanyanya kweI2 absorption kwakaonekwa munyaya yeLOS-perovskite, zvichiratidza kuti compact LOS inogona kudzivirira kuburitswa kweI2 kubva mufirimu reperovskite panguva yekunyudzwa kwechiedza. Mifananidzo yemafirimu e aged control neLOS perovskite inoratidzwa muzvikamu zveMifananidzo 3b na c. LOS perovskite ichiri nhema, nepo firimu zhinji rekutonga rashanduka yero. Ma spectra ekunyudzwa kweUV anoonekwa mufirimu rakanyudzwa anoratidzwa muMifananidzo 3b, c. Takaona kuti kunyudzwa kunoenderana neα mufirimu rekutonga kwakadzikira zviri pachena. Kuyerwa kweX-ray kwakaitwa kuratidza kushanduka kwechimiro chekristaro. Mushure memaawa makumi maviri nemana ekuvhenekerwa, control perovskite yakaratidza chiratidzo chakasimba cheyero δ-phase (11.8°), nepo LOS perovskite ichiri kuramba iine dema rakanaka (Mufananidzo 3d).
Maspectra ekunyudzwa kwetoluene anoonekwa neUV umo firimu rekudzora nefirimu reLOS zvakanyudzwa pasi pezuva rimwe chete kwemaawa makumi maviri nemana. Chikamu chinoratidza chivharo umo firimu rega rega rakanyudzwa muhuwandu hwakaenzana hwetoluene. b Maspectra ekunyudzwa kweUV-Vis efirimu rekudzora uye c LOS firimu usati wanyura uye mushure memaawa makumi maviri nemana pasi pezuva rimwe chete. Chikamu chinoratidza mufananidzo wefirimu rekuyedza. d Mapatani eX-ray diffraction ekudzora uye mafirimu eLOS usati wanyura uye mushure memaawa makumi maviri nemana. Mifananidzo yeSEM ​​yefirimu rekudzora e nefirimu f LOS mushure memaawa makumi maviri nemana ekuvhenekerwa. Data rekunobva rinopihwa muchimiro chemafaira edata rekunobva.
Takaita kuyera kwe scanning electron microscopy (SEM) kuti tione shanduko dze microstructure yefirimu re perovskite mushure memaawa makumi maviri nemana ekuvhenekerwa, sezvakaratidzwa muMifananidzo 3e, f. Mufirimu rekudzora, tsanga hombe dzakaparadzwa dzikaitwa tsono diki, izvo zvinoenderana nechimiro chechigadzirwa che δ-phase FAPbI3 (Mufananidzo 3e). Kune mafirimu e LOS, tsanga dze perovskite dzinoramba dziri mumamiriro akanaka (Mufananidzo 3f). Mhedzisiro yacho yakasimbisa kuti kurasikirwa kwe I kunokonzera zvakanyanya kuchinja kubva pachikamu chedema kuenda pachikamu chechiyero, nepo PbC2O4 ichidzikamisa chikamu chedema, ichidzivirira kurasikirwa kwe I. Sezvo huwandu hwenzvimbo dziri pamusoro hwakakwira zvakanyanya kupfuura muhuwandu hwetsanga,34 chikamu ichi chinowanzoitika pamusoro petsanga. panguva imwe chete ichiburitsa iodine uye ichiumba VI. Sezvakafanotaurwa neDFT, LOS inogona kudzivirira kuumbwa kwezvikanganiso zve VI uye kudzivirira kutama kwema I ions kuenda pamusoro pe perovskite.
Pamusoro pezvo, mhedzisiro yePbC2O4 layer pakudzivirira hunyoro hwemafirimu eperovskite mumhepo yemuchadenga (hunyoro hwe30-60%) yakadzidzwa. Sezvakaratidzwa muMufananidzo Wekuwedzera 9, LOS perovskite yakanga ichiri dema mushure memazuva gumi nemaviri, nepo firimu rekudzora rakashanduka yero. Mukuyerwa kweXRD, firimu rekudzora rinoratidza peak yakasimba pa11.8° inoenderana nechikamu che δ cheFAPbI3, nepo LOS perovskite ichichengetedza tsime rechikamu che α dema (Mufananidzo Wekuwedzera 10).
Steady-state photoluminescence (PL) uye time-resolved photoluminescence (TRPL) zvakashandiswa kudzidza passivation effect ye lead oxalate pamusoro pe perovskite. MuMufananidzo 4a inoratidza kuti LOS film yakawedzera PL intensity. Mumufananidzo wePL mapping, simba reLOS film panzvimbo yese ye10 × 10 μm2 rakakwirira kupfuura iro re control film (Supplementary Picture 11), zvichiratidza kuti PbC2O4 inobvisa perovskite firimu zvakaenzana. Lifetime ye carrier inotsanangurwa nekufungidzira kuora kweTRPL nebasa rimwe chete re exponential (Mufananidzo 4b). Lifetime ye carrier yeLOS film i5.2 μs, iyo yakareba kupfuura control film ine carrier lifetime ye0.9 μs, zvichiratidza kuderedzwa kwe surface nonradiative recombination.
PL inomira zvakanaka uye b-spectra ye PL yenguva pfupi yemafirimu eperovskite pagirazi. c SP curve yechishandiso (FTO/TiO2/SnO2/perovskite/spiro-OMeTAD/Au). d EQE spectrum uye Jsc EQE spectrum zvakabatanidzwa kubva kuchishandiso chinoshanda zvakanyanya. d Kutsamira kwechiedza chechinhu cheperovskite paVoc diagram. f Ongororo yakajairika yeMKRC uchishandisa ITO/PEDOT:PSS/perovskite/PCBM/Au clean hole device. VTFL ndiyo voltage yepamusoro yekuzadza trap. Kubva padata iri takaverenga density yetrap (Nt). Data resource rinopihwa muchimiro chemafaira edata resource.
Kuti tidzidze mhedzisiro ye lead oxalate layer pakushanda kwemudziyo, chimiro cheFTO/TiO2/SnO2/perovskite/spiro-OMeTAD/Au chakagadzirwa nenzira yekubatana. Tinoshandisa formamidine chloride (FACl) sechinhu chinowedzera kune perovskite precursor pachinzvimbo chemethylamine hydrochloride (MACl) kuti tiwane kushanda kuri nani kwemudziyo, sezvo FACl ichigona kupa kristalo yakanaka uye kudzivirira band gap yeFAPbI335 (ona Supplementary Figures 1 na2 kuti uenzanise zvakadzama). ). 12-14). IPA yakasarudzwa semushonga unodzivirira kunyungudika nekuti inopa kristalo yakanaka uye nzira yainodiwa mumafirimu eperovskite zvichienzaniswa nediethyl ether (DE) kana chlorobenzene (CB)36 (Supplementary Figures 15 na16). Ukobvu hwePbC2O4 hwakanyatsogadziriswa kuti huenzanise kukanganiswa kwedefect uye kutakurwa kwechaji nekugadzirisa huwandu hweoxalic acid (Supplementary Figure 17). Mifananidzo yeSEM ​​yezvikamu zvakasiyana-siyana zvezvishandiso zvekutonga zvakagadziriswa uye zveLOS inoratidzwa muMufananidzo weKuwedzera 18. Makove akajairika ehuwandu hwemazuva ano (CD) ezvishandiso zvekutonga neLOS anoratidzwa muMufananidzo 4c, uye maparameter akabviswa anopiwa muTafura yeKuwedzera 3. Masero ekutonga ekushanda nesimba guru (PCE) 23.43% (22.94%), Jsc 25.75 mA cm-2 (25.74 mA cm-2), Voc 1.16 V (1.16 V) uye reverse (forward) scan. The fill factor (FF) i78.40% (76.69%). PCE LOS PSC yepamusoro i25.39% (24.79%), Jsc i25.77 mA cm-2, Voc i1.18 V, FF i83.50% (81.52%) kubva kumashure (forward Scan kuenda). Mudziyo weLOS wakawana kushanda kwe photovoltaic kwakasimbiswa kwe24.92% murabhoritari ye photovoltaic yechitatu inovimbwa nayo (Mufananidzo Wekuwedzera 19). Kushanda kwe quantum efficiency (EQE) kwakapa Jsc yakabatanidzwa ye24.90 mA cm-2 (control) uye 25.18 mA cm-2 (LOS PSC), zvichiteerana, izvo zvaienderana zvakanaka neJsc yakayerwa mu standard AM 1.5 G spectrum (Mufananidzo .4d). ). Kugoverwa kwenhamba kwema PCE akayerwa ekudzora uye ma LOS PSC kunoratidzwa muSupplementary Figure 20.
Sezvakaratidzwa muMufananidzo 4e, hukama huripo pakati peVoc nechiedza hwakaverengerwa kuti huongorore mhedzisiro yePbC2O4 pakugadziriswazve kwenzvimbo ine trap-assisted surface. Kutsetseka kwemutsetse wakagadzirirwa mudziyo weLOS i1.16 kBT/sq, iyo iri pasi pemutsetse wakagadzirirwa mudziyo wekudzora (1.31 kBT/sq), zvichiratidza kuti LOS inobatsira pakudzivirira kudzokororwa kwenzvimbo ne decoys. Tinoshandisa tekinoroji ye space charge current limiting (SCLC) kuyera density yefirimu re perovskite nekuyera hunhu hwe dark IV hwemudziyo une gomba (ITO/PEDOT:PSS/perovskite/spiro-OMeTAD/Au) sezvakaratidzwa mumufananidzo. 4f Ratidza. Kuwanda kwetrap kunoverengerwa nefomura Nt = 2ε0εVTFL/eL2, apo ε iri relative dielectric constant yeperovskite film, ε0 ndiyo dielectric constant ye vacuum, VTFL ndiyo limiting voltage yekuzadza trap, e ndiyo charge, L ndiyo ukobvu hweperovskite film (650 nm). Defect density yeVOC device inoverengerwa kuva 1.450 × 1015 cm–3, iyo iri pasi pane defect density ye control device, iyo iri 1.795 × 1015 cm–3.
Mudziyo usina kuvhurwa wakaedzwa papower point yepamusoro (MPP) pasi pezuva rose pasi penitrogen kuti uongorore kugadzikana kwekushanda kwawo kwenguva refu (Mufananidzo 5a). Mushure memaawa 550, mudziyo weLOS wakaramba uine 92% yekushanda kwawo kwepamusoro, ukuwo kushanda kwemudziyo wekudzora kwakanga kwadzikira kusvika 60% yekushanda kwawo kwekutanga. Kupararira kwezvinhu mumudziyo wekare kwakayerwa ne time-of-flight secondary ion mass spectrometry (ToF-SIMS) (Mufananidzo 5b, c). Kuunganidzwa kukuru kweiodine kunogona kuonekwa munzvimbo yepamusoro yekudzora goridhe. Mamiriro ekudzivirira gasi risina kukuvadza zvinhu zvinokanganisa nharaunda zvakaita sehunyoro neokisijeni, zvichiratidza kuti nzira dzemukati (kureva, kufamba kweion) ndidzo dzinokonzera. Sekureva kwemigumisiro yeToF-SIMS, I- neAuI2-ions zvakaonekwa muAu electrode, zvichiratidza kupararira kweI kubva kuperovskite kuenda kuAu. Simba rechiratidzo cheI- neAuI2-ions mumudziyo wekudzora rakapetwa kagumi kupfuura reVOC sample. Mishumo yapfuura yakaratidza kuti kuyerera kwemaion kunogona kukonzera kudzikira kukuru kwehuro hwe spiro-OMeTAD uye corrosion ye top electrode layer, nokudaro zvichikanganisa kubatana kwe interfacial mu device37,38. Au electrode yakabviswa uye spiro-OMeTAD layer yakacheneswa kubva pasi ne chlorobenzene solution. Takabva tatsanangura firimu tichishandisa grazing incidence X-ray diffraction (GIXRD) (Mufananidzo 5d). Mhedzisiro inoratidza kuti firimu rekudzora rine diffraction peak iri pachena pa11.8°, nepo pasina diffraction peak itsva inoonekwa mu LOS sample. Mhedzisiro inoratidza kuti kurasikirwa kukuru kwemaion eI mufirimu rekudzora kunotungamira mukugadzirwa kwe δ phase, nepo mufirimu re LOS maitiro aya ari pachena kuti haana kudziviswa.
Maawa 575 ekutevera MPP nguva dzose kwechishandiso chisina kuvharwa mumhepo ine nitrogen uye chiedza chezuva chimwe chete chisina UV filter. Kugoverwa kweToF-SIMS kwe b I- uye c AuI2- ions muchishandiso chekudzora cheLOS MPP uye mudziyo wekukwegura. Mimvuri yeyero, girini neorenji inoenderana neAu, Spiro-OMeTAD uye perovskite. d GIXRD yefirimu reperovskite mushure mekuyedzwa kweMPP. Data rekwakabva rinopihwa muchimiro chemafaira edata rekwakabva.
Kufambiswa kwemhepo kunoenderana netembiricha kwakayerwa kusimbisa kuti PbC2O4 inogona kudzivirira kufamba kwemaion (Mufananidzo Wekuwedzera 21). Simba rekushanda (Ea) rekufamba kwemaion rinotsanangurwa nekuyera shanduko mukufambisa kwemhepo (σ) yefirimu reFAPbI3 patembiricha dzakasiyana (T) uye uchishandisa hukama hweNernst-Einstein: σT = σ0exp(−Ea/kBT), apo σ0 iri constant, kB ndiyo constant yeBoltzmann. Tinowana kukosha kweEa kubva pakutsetseka kweln(σT) zvichienzaniswa ne1/T, inova 0.283 eV yekudzora uye 0.419 eV yemudziyo weLOS.
Muchidimbu, tinopa hurongwa hwedzidziso yekuona nzira yekuora kweFAPbI3 perovskite uye pesvedzero yezvikanganiso zvakasiyana-siyana pakudzivirira simba kwekuchinja kwechikamu cheα-δ. Pakati pezvinokanganisa izvi, zvipingamupinyi zveVI zvinofungidzirwa kuti zvinogona kukonzera kuchinja kwechikamu kubva kuα kuenda kuδ. Rutivi rwakasimba rwePbC2O4 rusinganyungudike mumvura uye rwakagadzikana nemakemikari rwunounzwa kuti rugadzikane α-phase yeFAPbI3 nekudzivisa kuumbwa kwezvipingamupinyi zveI uye kufamba kwemaion eI. Iyi nzira inoderedza zvakanyanya kusanganiswa kweinterfacial non-radiative, inowedzera kushanda zvakanaka kwemasero ezuva kusvika ku25.39%, uye inovandudza kugadzikana kwekushanda. Mhedzisiro yedu inopa gwara rekuwana formamidine PSCs inoshanda uye yakagadzikana nekudzivisa kuchinja kwechikamu cheα-induced defect-induced α kuenda kuδ.
Titanium(IV) isopropoxide (TTIP, 99.999%) yakatengwa kubva kuSigma-Aldrich. Hydrochloric acid (HCl, 35.0–37.0%) uye ethanol (anhydrous) zvakatengwa kubva kuGuangzhou Chemical Industry. SnO2 (15 wt% tin(IV) oxide colloidal dispersion) yakatengwa kubva kuAlfa Aesar. Lead(II) iodide (PbI2, 99.99%) yakatengwa kubva kuTCI Shanghai (China). Formamidine iodide (FAI, ≥99.5%), formamidine chloride (FACl, ≥99.5%), methylamine hydrochloride (MACl, ≥99.5%), 2,2′,7,7′-tetrakis-(N , N-di-p) )-methoxyaniline)-9,9′-spirobifluorene (Spiro-OMeTAD, ≥99.5%), lithium bis(trifluoromethane)sulfonylimide (Li-TFSI, 99.95%), 4-tert -butylpyridine (tBP, 96%) yakatengwa kubva kuXi'an Polymer Light Technology Company (China). N,N-dimethylformamide (DMF, 99.8%), dimethyl sulfoxide (DMSO, 99.9%), isopropyl alcohol (IPA, 99.8%), chlorobenzene (CB, 99.8%), acetonitrile (ACN). Yakatengwa kubva kuSigma-Aldrich. Oxalic acid (H2C2O4, 99.9%) yakatengwa kubva kuMacklin. Makemikari ese akashandiswa sezvaakagamuchirwa pasina zvimwe zvakagadziridzwa.
Zvigadziko zveITO kana FTO (1.5 × 1.5 cm2) zvakacheneswa ne ultrasonic nesipo, acetone, uye ethanol kwemaminitsi gumi, zvichiteerana, uye zvobva zvaomeswa pasi pemvura ine nitrogen. Chigadziko chakakora cheTiO2 chakaiswa paFTO substrate uchishandisa mhinduro yetitanium diisopropoxybis (acetylacetonate) mu ethanol (1/25, v/v) yakaiswa pa500 °C kwemaminitsi makumi matanhatu. Kupararira kweSnO2 colloidal kwakasanganiswa nemvura yakasanganiswa ne 1:5. Pa substrate yakachena yakarapwa neUV ozone kwemaminitsi makumi maviri, firimu diki reSnO2 nanoparticles rakaiswa pa4000 rpm kwemasekonzi makumi matatu uye rakazopiswa pa150 °C kwemaminitsi makumi matatu. Kune perovskite precursor solution, 275.2 mg FAI, 737.6 mg PbI2 uye FACl (20 mol%) zvakanyungudutswa muDMF/DMSO (15/1) mixed solvent. Rutivi rweperovskite rwakagadzirwa nekuisa 40 μL ye perovskite precursor solution pamusoro peUV-ozone-treated SnO2 layer pa5000 rpm mumhepo yemhepo kwemaminitsi makumi maviri nemashanu. Masekonzi mashanu mushure menguva yekupedzisira, 50 μL yeMACl IPA solution (4 mg/mL) yakakurumidza kudonhedzwa pamusoro pe substrate semushonga unodzivisa kunyungudika. Zvadaro, mafirimu matsva akagadzirwa akasungirirwa pa150°C kwemaminitsi makumi maviri uye ipapo pa100°C kwemaminitsi gumi. Mushure mekutonhodza firimu reperovskite kusvika patembiricha yemukamuri, H2C2O4 solution (1, 2, 4 mg yakanyungudutswa mu1 mL IPA) yakatenderedzwa pa4000 rpm kwemaminitsi makumi matatu kuti ibvise perovskite pamusoro. Mushonga we spiro-OMeTAD wakagadzirwa nekusanganisa 72.3 mg spiro-OMeTAD, 1 ml CB, 27 µl tBP uye 17.5 µl Li-TFSI (520 mg mu 1 ml acetonitrile) wakaputirwa pafirimu pa4000 rpm mukati memasekondi makumi matatu. Pakupedzisira, 100 nm thick Au layer yakabviswa mu vacuum nechiyero che 0.05 nm/s (0~1 nm), 0.1 nm/s (2~15 nm) uye 0.5 nm/s (16~100 nm).
Kushanda kweSC kwemaseru ezuva eperovskite kwakayerwa uchishandisa Keithley 2400 metres pasi pechiedza chesolar simulator (SS-X50) pachiedza che100 mW/cm2 uye kwakasimbiswa uchishandisa maseru ezuva esilicon akagadziriswa. Kunze kwekunge zvataurwa neimwe nzira, ma SP curves akayerwa mubhokisi remagirovhosi rakazadzwa nenitrogen patembiricha yemukamuri (~25°C) munzira dzekuskena mberi nekudzoka shure (voltage step 20 mV, delay time 10 ms). Chifukidzo chemumvuri chakashandiswa kuona nzvimbo inoshanda ye0.067 cm2 yePSC yakayerwa. Kuyerwa kweEQE kwakaitwa mumhepo iri mumhepo uchishandisa PVE300-IVT210 system (Industrial Vision Technology(s) Pte Ltd) nechiedza che monochromatic chakatarisa pamudziyo. Kuti mudziyo ugare wakasimba, kuyedzwa kwemaseru ezuva asina kuvharwa kwakaitwa mubhokisi remagirovhosi enitrogen pa100 mW/cm2 pressure pasina UV filter. ToF-SIMS inoyerwa uchishandisa PHI nanoTOFII time-of-flight SIMS. Kuongororwa kwehudzamu kwakawanikwa uchishandisa pfuti ye4 kV Arion ine nzvimbo ye400×400 µm.
Kuyerwa kweX-ray photoelectron spectroscopy (XPS) kwakaitwa paThermo-VG Scientific system (ESCALAB 250) uchishandisa monochromatized Al Kα (yeXPS mode) pakumanikidzwa kwe5.0 × 10–7 Pa. Scanning electron microscopy (SEM) yakaitwa paJEOL-JSM-6330F system. Maumbirwo epamusoro uye kuomarara kwemafirimu eperovskite zvakayerwa uchishandisa atomic force microscopy (AFM) (Bruker Dimension FastScan). STEM neHAADF-STEM zvinochengetwa paFEI Titan Themis STEM. Maspectra eUV–Vis absorption akayerwa uchishandisa UV-3600Plus (Shimadzu Corporation). Space charge limiting current (SCLC) yakanyorwa paKeithley 2400 meter. Steady-state photoluminescence (PL) uye time-resolved photoluminescence (TRPL) of carrier lifetime decay zvakayerwa uchishandisa FLS 1000 photoluminescence spectrometer. Mifananidzo yePL mapping yakayerwa uchishandisa Horiba LabRam Raman system HR Evolution. Fourier transform infrared spectroscopy (FTIR) yakaitwa uchishandisa Thermo-Fisher Nicolet NXR 9650 system.
Mubasa iri, tinoshandisa nzira yeSSW path sampling kudzidza nzira yekuchinja chikamu kubva pa α-phase kuenda ku δ-phase. Munzira yeSSW, kufamba kwenzvimbo ine simba rinokwanisa kunotsanangurwa negwara re random soft mode (second derivative), iyo inobvumira kudzidza kwakadzama uye kwakanangana nenzvimbo ine simba rinokwanisa. Mubasa iri, nzira yesampling inoitwa pa 72-atom supercell, uye anopfuura 100 initial/final state (IS/FS) pairs anounganidzwa padanho reDFT. Zvichibva padata reIS/FS pairwise, nzira inobatanidza chimiro chekutanga nechimiro chekupedzisira inogona kutsanangurwa nekubatana pakati pemaatomu, uye ipapo kufamba kwenzira mbiri pamwe chete ne variable unit surface kunoshandiswa kuona zviri nyore nzira yekuchinja. (VK-DESV). Mushure mekutsvaga mamiriro ekuchinja, nzira ine chipingamupinyi chakaderera inogona kutsanangurwa nekuisa zvipingamupinyi zvesimba padanho.
Kuverenga kwese kweDFT kwakaitwa uchishandisa VASP (vhezheni 5.3.5), uko ma electron-ion interactions emaatomu eC, N, H, Pb, uye I anomiririrwa ne projected amplified wave (PAW). Basa re exchange correlation rinotsanangurwa ne generalized gradient approximation muPerdue-Burke-Ernzerhoff parametrization. Muganho wesimba rema plane was set to 400 eV. Monkhorst-Pack k-point grid ine saizi ye (2 × 2 × 1). Kune zvese zvivakwa, lattice uye atomic positions zvakagadziriswa zvizere kusvika maximum stress component iri pasi pe 0.1 GPa uye maximum force component iri pasi pe 0.02 eV/Å. Mumuenzaniso wepamusoro, pamusoro peFAPbI3 pane 4 layers, below layer ine ma fixed atoms anotevedzera muviri weFAPbI3, uye top layers nhatu dzinogona kufamba zvakasununguka panguva ye optimization process. Rutivi rwePbC2O4 rwakaita 1 ML ukobvu uye rwuri pamusoro peI-terminal yeFAPbI3, uko Pb yakasungirirwa ku1 I uye 4 O.
Kuti uwane rumwe ruzivo nezve dhizaini yekudzidza, ona Natural Portfolio Report Abstract yakabatana nechinyorwa chino.
Ruzivo rwese rwakawanikwa kana kuongororwa panguva yekudzidza uku rwuri muchinyorwa chakabudiswa, pamwe chete neruzivo rwunotsigira uye mafaira edata raw data. Ruzivo rwawakawana muchidzidzo ichi runowanikwa pa https://doi.org/10.6084/m9.figshare.2410016440. Ruzivo rwekutanga rwunopihwa kuchinyorwa chino.
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