Modulated CH3NH3PbI3−xBrx film for efficient perovskite solar cells exceeding 18%

Abstract

The organic-inorganic lead halide perovskite layer is a crucial factor for the high performance perovskite solar cell (PSC). We introduce CH3NH3Br in the precursor solution to prepare CH3NH3PbI3−xBrx hybrid perovskite, and an uniform perovskite layer with improved crystallinity and apparent grain contour is obtained, resulting in the significant improvement of photovoltaic performance of PSCs. The effects of CH3NH3Br on the perovskite morphology, crystallinity, absorption property, charge carrier dynamics and device characteristics are discussed, and the improvement of open circuit voltage of the device depended on Br doping is confirmed. Based on above, the device based on CH3NH3PbI2.86Br0.14 exhibits a champion power conversion efficiency (PCE) of 18.02%. This study represents an efficient method for high-performance perovskite solar cell by modulating CH3NH3PbI3−xBrx film.

CH3NH3Br Additive for Enhanced Photovoltaic Performance and Air Stability of Planar Perovskite Solar Cells prepared by Two‐Step Dipping Method

“…Snaith's group found that perovskite material with hybrid halides such as CH 3 NH 3 PbI 3− x Cl x not only showed higher stability when processing in air but also had much longer carrier diffusion lengths compared with pure MAPbI 3 . MAPbI 3− x Br x and CH 3 NH 3 Br (MABr) additive‐treated MAPbI 3 materials have also been confirmed to have improved performance and stability …”

“…Accordingly, the observed phenomena following the use of the MABr additive in this work are consistent with those reported in Ref. .…”

Interface Modification by Ionic Liquid: A Promising Candidate for Indoor Light Harvesting and Stability Improvement of Planar Perovskite Solar Cells

“…[6] In a planar PSC, hole-and/or electron-transporting layers are always introduced to manipulate the carrier behavior in the device. [1,[7][8][9][10][11][12][13][14][15][16][17][18][19] It can serve as an efficient hole-blocking layer at the interface between [6,6]-phenyl-C61-butyric acid methyl ester) (PCBM) and metal contact by its wide bandgap. [3][4][5] In addition to the tailoring role of the energy levels, the upper interfacial film can also act as a significant protecting layer for the perovskite layer.…”

Caesium for Perovskite Solar Cells: An Overview

“…In fact, after doping, the per-ovskite band-gap was blue-shifted accordingly to the broadening of the band-gap of plain thin films after the addition of Cs + or Br À ions. [110][111][112] The perovskite with 0.9:1:0.1 ratio of CH 3 NH 3 I:PbI 2 :CsBr showed aP CE of 13.6 %, which is much highert han the 9.8 %v alue without doping.…”

“…To solve these issues, in 2014 Figure 1. The crystalline structures of A) 2D and B, C) 3D perovskites; D) Schematic illustrations of (110), (002), ( 112) and (200) crystal planes from ap erpendicular view,f or perovskites composedo f( MAPbI 3 ) 1Àx (CsPbBr 3 ) x with x ranging from 0t o0 .2.Adapted and reprinted with permission. [97,116] of Cs-doping by replacing the organic cation in the MAPbI 3 structurew ith an inorganic cation.…”