Controllable selenization kinetics via stabilizing Se concentration enables 14.33% CZTSSe solar cells
Abstract
The early-stage uniformity and stability of selenium (Se) vapor during selenization critically determine the power conversion efficiency (PCE) of Cu2ZnSn(S,Se)4 (CZTSSe) devices. However, traditional large-volume graphite chambers (Ctrl) provide an overly spacious diffusion environment, leading to delayed Se supply and concentration fluctuations that promote void defects and Cu–Zn disorder. To address this, we propose a small-sized graphite box (S-box) that stabilizes Se delivery at the source by confining the diffusion volume, shortening the mass-transport path, and accelerating concentration equilibration. COMSOL Multiphysics simulations verify that this design markedly improves diffusion efficiency and rapidly establishes a stable concentration field; correspondingly, experiments show that S-box films exhibit higher crystallinity, reduced Sn2+ content, a denser bilayer structure with fewer voids, and a significantly lower overall defect density. Low-temperature photoluminescence further indicates that non-radiative recombination associated with VCu and band tail states is effectively suppressed. Accordingly, devices fabricated with the S-box achieve a champion efficiency of 14.33% (certified at 14.07%), establishing “restricting the Se vapor diffusion space” as the key point of selenization optimization.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (15)
Yuan Li
Tan Guo
Beijing National Laboratory for Condensed Matter Physics, Renewable Energy Laboratory, Institute of Physics, Chinese Academy of Sciences 2 , Beijing 100190,
Letu Siqin
Inner Mongolia Key Laboratory of Semiconductor Photovoltaic Technology and Energy Materials, School of Physical Science and Technology, Center for Quantum Physics and Technologies, Inner Mongolia University 1 , Hohhot 010021,
Xiao Xu
Jinlin Wang
Shuyu Li
State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest Agriculture and Forestry University
Yaqing Cui
Inner Mongolia Key Laboratory of Semiconductor Photovoltaic Technology and Energy Materials, School of Physical Science and Technology, Center for Quantum Physics and Technologies, Inner Mongolia University 1 , Hohhot 010021,
Menghan Jiao
Beijing National Laboratory for Condensed Matter Physics, Renewable Energy Laboratory, Institute of Physics, Chinese Academy of Sciences 2 , Beijing 100190,
Bowen Zhang
Shudan Chen
Beijing National Laboratory for Condensed Matter Physics, Renewable Energy Laboratory, Institute of Physics, Chinese Academy of Sciences 2 , Beijing 100190,
Jingchen Wang
Beijing National Laboratory for Condensed Matter Physics, Renewable Energy Laboratory, Institute of Physics, Chinese Academy of Sciences 2 , Beijing 100190,
Ruijian Liu
Inner Mongolia Key Laboratory of Semiconductor Photovoltaic Technology and Energy Materials, School of Physical Science and Technology, Center for Quantum Physics and Technologies, Inner Mongolia University 1 , Hohhot 010021,
Jiangjian Shi
Chengjun Zhu
School of Physical Science and Technology, Inner Mongolia University 3 , 2352 West University Road, Huhhot, Inner Mongolia 010021,
Qingbo Meng