Achieving high open-circuit voltage in efficient kesterite solar cells via lanthanide europium ion induced carrier lifetime enhancement

• DOI: 10.1016/j.nanoen.2024.109448
• Publication Date: 2024-03-04T17:28:33Z
• Authors: Xingye Chen; Yunhai Zhao; Nafees Ahmad; Jun Zhao; Zhuanghao Zheng; Zhenghua Su; Xiaogang Peng; Xuejin Li; Xianghua Zhang; Ping Fan; Guangxing Liang; Shuo Chen
• Keywords: carrier lifetime; open-circuit voltage; cation doping; [CHIM]Chemical Sciences; Eu ions; CZTSSe solar cells

International audience<br/>Short carrier lifetimes is a key challenge limiting the open-circuit voltage (VOC) and power conversion efficiency (PCE) of kesterite Cu2ZnSn(S,Se)4 (CZTSSe) solar cells. In this work, for the first time, lanthanide europium (Eu) ions have been introduced into Ag-incorporated CZTSSe absorber layer, which can modify the selenization reaction pathway during the initial selenization process, leading to high-quality (Ag, Eu)-CZTSSe absorber with large compact crystal grains and benign surface potential fluctuations. This innovative absorber engineering can also optimize defects dynamics with less detrimental defects and defects-assisted non-radiative recombination. Thus, significantly enhanced minority carrier lifetimes from 0.97 to 3.15 ns can be achieved, representing one of the top values among various bulk and/or interface engineering treated CZTSSe. The champion CZTSSe thin-film solar cell exhibits an impressive VOC of 545.6 mV, accompanied with a stimulating increase in PCE from 10.68% to 13.30%. These findings underscore the potential of lanthanide cation doping to drive significant advancements in CZTSSe photovoltaic technology, and therefore promoting its further development and future applications.<br/>