Cao Lei, Zhou Zhengji, Zhou Wenhui, Kou Dongxing, Meng Yuena, Yuan Shengjie, Qi Yafang, Han Litao, Tian Qingwen, Wu Sixin, Liu Shengzhong Frank
Key Lab for Special Functional Materials, Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, and School of Materials, Henan University, Kaifeng, 475004, China.
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China.
Small. 2024 Mar;20(9):e2304866. doi: 10.1002/smll.202304866. Epub 2023 Oct 20.
Grain boundaries (GBs)-triggered severe non-radiative recombination is recently recognized as the main culprits for carrier loss in polycrystalline kesterite photovoltaic devices. Accordingly, further optimization of kesterite-based thin film solar cells critically depends on passivating the grain interfaces of polycrystalline Cu ZnSn(S,Se) (CZTSSe) thin films. Herein, 2D material of graphene is first chosen as a passivator to improve the detrimental GBs. By adding graphene dispersion to the CZTSSe precursor solution, single-layer graphene is successfully introduced into the GBs of CZTSSe absorber. Due to the high carrier mobility and electrical conductivity of graphene, GBs in the CZTSSe films are transforming into electrically benign and do not act as high recombination sites for carrier. Consequently, benefitting from the significant passivation effect of GBs, the use of 0.05 wt% graphene additives increases the efficiency of CZTSSe solar cells from 10.40% to 12.90%, one of the highest for this type of cells. These results demonstrate a new route to further increase kesterite-based solar cell efficiency by additive engineering.
晶界引发的严重非辐射复合最近被认为是多晶锡基硫属化合物光伏器件中载流子损失的主要原因。因此，基于锡基硫属化合物的薄膜太阳能电池的进一步优化关键取决于钝化多晶Cu ZnSn(S,Se)（CZTSSe）薄膜的晶粒界面。在此，首先选择二维材料石墨烯作为钝化剂来改善有害的晶界。通过将石墨烯分散体添加到CZTSSe前驱体溶液中，单层石墨烯成功引入到CZTSSe吸收体的晶界中。由于石墨烯具有高载流子迁移率和电导率，CZTSSe薄膜中的晶界转变为电良性的，不再作为载流子的高复合位点。因此，受益于晶界的显著钝化效果，使用0.05 wt%的石墨烯添加剂可将CZTSSe太阳能电池的效率从10.40%提高到12.90%，这是此类电池中最高的效率之一。这些结果展示了一种通过添加剂工程进一步提高基于锡基硫属化合物的太阳能电池效率的新途径。
