Controlling Selenization Equilibrium Enables High-Quality Kesterite Absorbers for Efficient Solar Cells

Xiao Xu; Jiazheng Zhou; Kang Yin; Jinlin Wang; Licheng Lou; Menghan Jiao; Bowen Zhang; Dongmei Li; Jiangjian Shi; Huijue Wu; Yanhong Luo; Qingbo Meng

doi:10.1038/s41467-023-42460-7

Controlling Selenization Equilibrium Enables High-Quality Kesterite Absorbers for Efficient Solar Cells

Nat Commun. 2023 Oct 20;14(1):6650. doi: 10.1038/s41467-023-42460-7.

Authors

Xiao Xu^#^{1

2}, Jiazheng Zhou^#^{1

2}, Kang Yin^{1

2}, Jinlin Wang^{1

2}, Licheng Lou^{1

2}, Menghan Jiao^{1

2}, Bowen Zhang^{1

2}, Dongmei Li^{1

2

3}, Jiangjian Shi⁴, Huijue Wu¹, Yanhong Luo^{5

6

7}, Qingbo Meng^{8

9

10}

Affiliations

¹ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences (CAS), Beijing, 100190, China.
² School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
³ Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China.
⁴ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences (CAS), Beijing, 100190, China. shijj@iphy.ac.cn.
⁵ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences (CAS), Beijing, 100190, China. yhluo@iphy.ac.cn.
⁶ School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China. yhluo@iphy.ac.cn.
⁷ Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China. yhluo@iphy.ac.cn.
⁸ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences (CAS), Beijing, 100190, China. qbmeng@iphy.ac.cn.
⁹ Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China. qbmeng@iphy.ac.cn.
¹⁰ Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China. qbmeng@iphy.ac.cn.

^# Contributed equally.

Abstract

Kesterite Cu₂ZnSn(S, Se)₄ is considered one of the most competitive photovoltaic materials due to its earth-abundant and nontoxic constituent elements, environmental friendliness, and high stability. However, the preparation of high-quality Kesterite absorbers for photovoltaics is still challenging for the uncontrollability and complexity of selenization reactions between metal element precursors and selenium. In this study, we propose a solid-liquid/solid-gas (solid precursor and liquid/vapor Se) synergistic reaction strategy to precisely control the selenization process. By pre-depositing excess liquid selenium, we provide the high chemical potential of selenium to facilitate the direct and rapid formation of the Kesterite phase. The further optimization of selenium condensation and subsequent volatilization enables the efficient removal of organic compounds and thus improves charge transport in the absorber film. As a result, we achieve high-performance Kesterite solar cells with total-area efficiency of 13.6% (certified at 13.44%) and 1.09 cm²-area efficiency of 12.0% (certified at 12.1%).