Skip to main content
eScholarship
Open Access Publications from the University of California

UC Berkeley

UC Berkeley Previously Published Works bannerUC Berkeley

Dipolar cations confer defect tolerance in wide-bandgap metal halide perovskites.

  • Author(s): Tan, Hairen;
  • Che, Fanglin;
  • Wei, Mingyang;
  • Zhao, Yicheng;
  • Saidaminov, Makhsud I;
  • Todorović, Petar;
  • Broberg, Danny;
  • Walters, Grant;
  • Tan, Furui;
  • Zhuang, Taotao;
  • Sun, Bin;
  • Liang, Zhiqin;
  • Yuan, Haifeng;
  • Fron, Eduard;
  • Kim, Junghwan;
  • Yang, Zhenyu;
  • Voznyy, Oleksandr;
  • Asta, Mark;
  • Sargent, Edward H
  • et al.
Abstract

Efficient wide-bandgap perovskite solar cells (PSCs) enable high-efficiency tandem photovoltaics when combined with crystalline silicon and other low-bandgap absorbers. However, wide-bandgap PSCs today exhibit performance far inferior to that of sub-1.6-eV bandgap PSCs due to their tendency to form a high density of deep traps. Here, we show that healing the deep traps in wide-bandgap perovskites-in effect, increasing the defect tolerance via cation engineering-enables further performance improvements in PSCs. We achieve a stabilized power conversion efficiency of 20.7% for 1.65-eV bandgap PSCs by incorporating dipolar cations, with a high open-circuit voltage of 1.22 V and a fill factor exceeding 80%. We also obtain a stabilized efficiency of 19.1% for 1.74-eV bandgap PSCs with a high open-circuit voltage of 1.25 V. From density functional theory calculations, we find that the presence and reorientation of the dipolar cation in mixed cation-halide perovskites heals the defects that introduce deep trap states.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Main Content
For improved accessibility of PDF content, download the file to your device.
Current View