One-Step Gas-Solid-Phase Diffusion-Induced Elemental Reaction for Bandgap-Tunable CuaAgm1Bim2In/CuI Thin Film Solar Cells

Erchuang Fan; Manying Liu; Kangni Yang; Siyu Jiang; Bingxin Li; Dandan Zhao; Yanru Guo; Yange Zhang; Peng Zhang; Chuantian Zuo; Liming Ding; Zhi Zheng

doi:10.1007/s40820-023-01033-5

One-Step Gas-Solid-Phase Diffusion-Induced Elemental Reaction for Bandgap-Tunable Cu_aAg_m1Bi_m2I_n/CuI Thin Film Solar Cells

Nanomicro Lett. 2023 Mar 2;15(1):58. doi: 10.1007/s40820-023-01033-5.

Authors

Erchuang Fan^{1

2}, Manying Liu³, Kangni Yang¹, Siyu Jiang^{1

2}, Bingxin Li¹, Dandan Zhao¹, Yanru Guo¹, Yange Zhang¹, Peng Zhang², Chuantian Zuo⁴, Liming Ding⁵, Zhi Zheng^{6

7}

Affiliations

¹ Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, College of Chemical and Materials Engineering, Institute of Surface Micro and Nano Materials, Xuchang University, Xuchang, 461000, People's Republic of China.
² School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, People's Republic of China.
³ Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, College of Chemical and Materials Engineering, Institute of Surface Micro and Nano Materials, Xuchang University, Xuchang, 461000, People's Republic of China. manyingliu988@xcu.edu.cn.
⁴ Center for Excellence in Nanoscience (CAS), Key Laboratory of Nanosystem and Hierarchical Fabrication (CAS), National Center for Nanoscience and Technology, Beijing, 100190, People's Republic of China.
⁵ Center for Excellence in Nanoscience (CAS), Key Laboratory of Nanosystem and Hierarchical Fabrication (CAS), National Center for Nanoscience and Technology, Beijing, 100190, People's Republic of China. ding@nanoctr.cn.
⁶ Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, College of Chemical and Materials Engineering, Institute of Surface Micro and Nano Materials, Xuchang University, Xuchang, 461000, People's Republic of China. zzheng@xcu.edu.cn.
⁷ School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, People's Republic of China. zzheng@xcu.edu.cn.

Abstract

Lead-free inorganic copper-silver-bismuth-halide materials have attracted more and more attention due to their environmental friendliness, high element abundance, and low cost. Here, we developed a strategy of one-step gas-solid-phase diffusion-induced reaction to fabricate a series of bandgap-tunable Cu_aAg_m1Bi_m2I_n/CuI bilayer films due to the atomic diffusion effect for the first time. By designing and regulating the sputtered Cu/Ag/Bi metal film thickness, the bandgap of Cu_aAg_m1Bi_m2I_n could be reduced from 2.06 to 1.78 eV. Solar cells with the structure of FTO/TiO₂/Cu_aAg_m1Bi_m2I_n/CuI/carbon were constructed, yielding a champion power conversion efficiency of 2.76%, which is the highest reported for this class of materials owing to the bandgap reduction and the peculiar bilayer structure. The current work provides a practical path for developing the next generation of efficient, stable, and environmentally friendly photovoltaic materials.

Keywords: Bandgap tuning; CuaAgm1Bim2In; Elemental reaction; Gas–solid phase; Solar cells.