Cooperatively controlling unpleasant defects in kesterite solar cells by introducing La3+ ions induced Na diffusion

G Guonan Cui (School of Physics and Electronic Information, Inner Mongolia Autonomous Region Engineering Research Center for Rare Earth Functions and New Energy Storage Materials, Inner Mongolia Normal University 1 , 81 Zhaowuda Road, Huhhot, Inner Mongolia 010022,) Y Yanchun Yang L Lulu Bai (School of Physics and Electronic Information, Inner Mongolia Autonomous Region Engineering Research Center for Rare Earth Functions and New Energy Storage Materials, Inner Mongolia Normal University 1 , 81 Zhaowuda Road, Huhhot, Inner Mongolia 010022,) Y Yanqing Liu Z Zhihui Gong (School of Physics and Electronic Information, Inner Mongolia Autonomous Region Engineering Research Center for Rare Earth Functions and New Energy Storage Materials, Inner Mongolia Normal University 1 , 81 Zhaowuda Road, Huhhot, Inner Mongolia 010022,) Y Yuze Sun X Xu Wang J Junjie Bao (Inner Mongolia Autonomous Region Engineering Research Center for Rare Earth Functions and New Energy Storage Materials, Inner Mongolia Normal University 1 , 81 Zhaowuda Road, Hohhot, Inner Mongolia 010022,) S 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) C Chengjun Zhu (School of Physical Science and Technology, Inner Mongolia University 3 , 2352 West University Road, Huhhot, Inner Mongolia 010021,)

Abstract

Hindering the unpleasant bulk defects is considered an effective measure to improve the photoelectric conversion efficiency (PCE) of Cu2ZnSn(S, Se)4 (CZTSSe) thin film solar cells. In this work, rare earth La3+ ions were introduced into the Cu2ZnSn(S, Se)4 absorption layer and induced Na diffusion from the substrate, collaborating to optimize their unpleasant Sn-related and Cu-related defects. Na diffusion can reduce the CuZn defects and improve the crystallinity of CZTSSe films. The introduced La can locate at the grain boundaries of films, suppress the SnZn bulk defects, and enhance the surface potential distribution of film. Cooperation optimization helps increase the PCE of the device. With dual cation (Ag and La) doping, the PCE of the champion CZTSSe device is improved to 11.6%. Our conclusions supplement the understanding of the existence form and influence mechanism of La in kesterite materials and provide an insight into the performance optimization of kesterite devices.

Article Details

Volume / Issue Vol. 127, Issue 23
Published December 08, 2025
ISSN 0003-6951
Publisher American Institute of Physics

Journal Info

Applied Physics Letters

American Institute of Physics

ISSN: 0003-6951 Physical Sciences

Authors (10)

G

Guonan Cui

School of Physics and Electronic Information, Inner Mongolia Autonomous Region Engineering Research Center for Rare Earth Functions and New Energy Storage Materials, Inner Mongolia Normal University 1 , 81 Zhaowuda Road, Huhhot, Inner Mongolia 010022,

Y

Yanchun Yang

L

Lulu Bai

School of Physics and Electronic Information, Inner Mongolia Autonomous Region Engineering Research Center for Rare Earth Functions and New Energy Storage Materials, Inner Mongolia Normal University 1 , 81 Zhaowuda Road, Huhhot, Inner Mongolia 010022,

Y

Yanqing Liu

Z

Zhihui Gong

School of Physics and Electronic Information, Inner Mongolia Autonomous Region Engineering Research Center for Rare Earth Functions and New Energy Storage Materials, Inner Mongolia Normal University 1 , 81 Zhaowuda Road, Huhhot, Inner Mongolia 010022,

Y

Yuze Sun

X

Xu Wang

J

Junjie Bao

Inner Mongolia Autonomous Region Engineering Research Center for Rare Earth Functions and New Energy Storage Materials, Inner Mongolia Normal University 1 , 81 Zhaowuda Road, Hohhot, Inner Mongolia 010022,

S

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

C

Chengjun Zhu

School of Physical Science and Technology, Inner Mongolia University 3 , 2352 West University Road, Huhhot, Inner Mongolia 010021,