Enhanced carrier transport over grain boundaries in lead-free CH3NH3Sn(I1-xBr x)3 (0 ≤ x ≤ 1) perovskite solar cells

Bich Phuong Nguyen, Hye Ri Jung, Juran Kim, William Jo

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

This paper reports on grain boundary (GB) roles in lead-free tin halide perovskite thin films. Nano scale spatial mapping of charge separation efficiency in methylammonium tin halide (MASn(I1-xBr x )3, MA = CH3NH3) thin films were constructed by Kelvin probe force microscopy and conductive atomic force microscopy (C-AFM). We observed downward band bending at GBs under dark conditions and higher surface photovoltage along the GBs, confirmed by C-AFM which showed high local current flows along the GBs. The band bending degree and local current intensity were affected by the Br/I ratio. Photo-generated carriers were more effectively separated and collected at GBs with increased Br content, and hysteresis was observed in Br-rich Sn-halide perovskite.

Original languageEnglish
Article number314005
JournalNanotechnology
Volume30
Issue number31
DOIs
StatePublished - 8 May 2019

Keywords

  • band bending
  • charge separation and collection
  • grain boundary
  • grain size
  • tin-based perovskite

Fingerprint

Dive into the research topics of 'Enhanced carrier transport over grain boundaries in lead-free CH3NH3Sn(I1-xBr x)3 (0 ≤ x ≤ 1) perovskite solar cells'. Together they form a unique fingerprint.

Cite this