Improved Photovoltaic Performance of CsPbI2Br Perovskite Films via Bivalent Metal Chloride Doping

Hong Wei Qiao,Mengjiong Chen,Qilin Cheng,Ziren Zhou,Yu Hou,Hua Gui Yang

doi:10.3389/fenrg.2021.692059

Hong Wei Qiao, Mengjiong Chen + Show 4 more

Open Access

https://doi.org/10.3389/fenrg.2021.692059

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Abstract

Cesium-based all-inorganic perovskite absorbers have attracted increasing attention due to their superior thermal stability, compared to their organic–inorganic counterparts. Up to now, it is a challenge to fabricate high-efficiency all-inorganic perovskite solar cells (PSCs) with low defect densities. Herein, we used bivalent metal chloride salts (SrCl2 and NiCl2) to optimize CsPbI2Br films. The experimental results indicate that this method could deliver high-quality films with improved electronic property. As a result, the champion device based on the 0.01 M SrCl2–doped CsPbI2Br film achieved a power conversion efficiency (PCE) of 16.07% with a high open voltage (VOC) of 1,322 mV, which is about 18% higher than that of the pristine device.

Highlights

Lead halide perovskites are promising photovoltaic materials because of their tunable bandgap, long carrier diffusion length, and easy fabrication (Chen et al, 2015; Shi et al, 2015; Lin et al, 2018; Yang et al, 2019a; Qiao et al, 2019; Fang et al, 2020; Qiao et al, 2020)
We revealed that certain amount of metal chloride salts is substantially beneficial for the formation of the perovskite with less trap sites, while excess metal chloride salts are detrimental to the perovskite films
The deposition of CsPbI2Br perovskites is based on the spincoating of perovskite precursors dissolved in DMSO solution

Summary

INTRODUCTION

Lead halide perovskites are promising photovoltaic materials because of their tunable bandgap, long carrier diffusion length, and easy fabrication (Chen et al, 2015; Shi et al, 2015; Lin et al, 2018; Yang et al, 2019a; Qiao et al, 2019; Fang et al, 2020; Qiao et al, 2020). Controlling the deposition process of perovskite thin films could optimize film coverage at a long-range scale, as well as reducing the atomic crystal defects (Chen et al, 2019; Duan et al, 2020; Liu et al, 2020). Processing parameters, such as coating speed and annealing temperature, have been initially studied in previous reports (Yu and Gao, 2017; Zhang et al, 2020a). We studied the effect of bivalent metal chloride salts (SrCl2 and NiCl2) on the film quality of the CsPbI2Br perovskite. The wavelength of the laser was 532 nm, the repeating frequency was about 10 Hz, and the pulse width was less than 10 ns

RESULTS AND DISCUSSION

CONCLUSION

DATA AVAILABILITY STATEMENT