TY - JOUR
T1 - Control over Self-Doping in High Band Gap Perovskite Films
AU - Kulbak, Michael
AU - Levine, Igal
AU - Barak-Kulbak, Einav
AU - Gupta, Satyajit
AU - Zohar, Arava
AU - Balberg, Isaac
AU - Hodes, Gary
AU - Cahen, David
N1 - Publisher Copyright:
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2018/8/16
Y1 - 2018/8/16
N2 - It is reported how differences in the composition of high bandgap Pb bromide-based perovskites affect their carrier diffusion length and junction type. Pb-based, APbX3, halide perovskite (HaP) films and devices are studied, where A can be a mixture of formamidinium, methylammonium (MA), and Cs, and X a mixture of Br and Cl, using a combination of dark- and photoconductivity and steady-state photocarrier grating. The results show the cation and anion compositions affect both majority and minority carrier diffusion lengths. In particular, using electron beam-induced current measurements, FTO\dTiO2mp-TiO2HaP\PTAA (poly-triarylamine)\Au devices are studied. The results enable identifying junction and built-in voltage formation and track position and size of the space charge region width with changes in the HaP composition. As far as it is known, it is found for the first time that a mixed-cation HaP forms a junction that has characteristics of a p-i-n one, with relatively long and comparable carrier diffusion lengths, while the single cation-based bromide HaPs form clear p-n junctions at the interface with the TiO2 [pure CsPbBr3 and MAPbBr3(Cl)] or a buried one (MAPbBr3) and shorter diffusion lengths. These differences are attributed to lower carrier density in MAPbBr3, and especially in the mixed cation HaP, which is comparable to iodide-based HaP films.
AB - It is reported how differences in the composition of high bandgap Pb bromide-based perovskites affect their carrier diffusion length and junction type. Pb-based, APbX3, halide perovskite (HaP) films and devices are studied, where A can be a mixture of formamidinium, methylammonium (MA), and Cs, and X a mixture of Br and Cl, using a combination of dark- and photoconductivity and steady-state photocarrier grating. The results show the cation and anion compositions affect both majority and minority carrier diffusion lengths. In particular, using electron beam-induced current measurements, FTO\dTiO2mp-TiO2HaP\PTAA (poly-triarylamine)\Au devices are studied. The results enable identifying junction and built-in voltage formation and track position and size of the space charge region width with changes in the HaP composition. As far as it is known, it is found for the first time that a mixed-cation HaP forms a junction that has characteristics of a p-i-n one, with relatively long and comparable carrier diffusion lengths, while the single cation-based bromide HaPs form clear p-n junctions at the interface with the TiO2 [pure CsPbBr3 and MAPbBr3(Cl)] or a buried one (MAPbBr3) and shorter diffusion lengths. These differences are attributed to lower carrier density in MAPbBr3, and especially in the mixed cation HaP, which is comparable to iodide-based HaP films.
KW - doping
KW - high voltage
KW - perovskites
KW - photo-transport properties
KW - photovoltaics
UR - http://www.scopus.com/inward/record.url?scp=85051583695&partnerID=8YFLogxK
U2 - 10.1002/aenm.201800398
DO - 10.1002/aenm.201800398
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AN - SCOPUS:85051583695
SN - 1614-6832
VL - 8
JO - Advanced Energy Materials
JF - Advanced Energy Materials
IS - 23
M1 - 1800398
ER -