Control over Self-Doping in High Band Gap Perovskite Films

Michael Kulbak, Igal Levine, Einav Barak-Kulbak, Satyajit Gupta, Arava Zohar, Isaac Balberg, Gary Hodes, David Cahen

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


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.

Original languageEnglish
Article number1800398
JournalAdvanced Energy Materials
Issue number23
StatePublished - 16 Aug 2018
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


  • doping
  • high voltage
  • perovskites
  • photo-transport properties
  • photovoltaics


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