A Bifunctional Carbazide Additive For Durable CsSnI3 Perovskite Solar Cells

作者：Duan, Chenghao; Zou, Feilin; Wen, Qiaoyun; Qin, Minchao; Li, Jiong; Chen, Chang; Lu, Xinhui; Ding, Liming; Yan, Keyou^*

来源：Advanced Materials, 2023, 35(26).

DOI：10.1002/adma.202300503

• antioxidation
• carbazide
• coordination
• CsSnI3 perovskite
• solar cells

Inorganic CsSnI3 with low toxicity and a narrow bandgap is a promising photovoltaic material. However, the performance of CsSnI3 perovskite solar cells (PSCs) is much lower than that of Pb-based and hybrid Sn-based (e.g., CsPbX3 and CH(NH2)(2)SnX3) PSCs, which may be attributed to its poor film-forming property and the deep traps induced by Sn4+. Here, a bifunctional additive carbazide (CBZ) is adapted to deposit a pinhole-free film and remove the deep traps via two-step annealing. The lone electrons of the -NH2 and -CO units in CBZ can coordinate with Sn2+ to form a dense film with large grains during the phase transition at 80 degrees C. The decomposition of CBZ can reduce Sn4+ to Sn2+ during annealing at 150 degrees C to remove the deep traps. Compared with the control device (4.12%), the maximum efficiency of the CsSnI3:CBZ PSC reaches 11.21%, which is the highest efficiency of CsSnI3 PSC reported to date. A certified efficiency of 10.90% is obtained by an independent photovoltaic testing laboratory. In addition, the unsealed CsSnI3:CBZ devices maintain initial efficiencies of approximate to 100%, 90%, and 80% under an inert atmosphere (60 days), standard maximum power point tracking (650 h at 65 degrees C), and ambient air (100 h), respectively.

• 单位
  中国科学院; 国家纳米科学中心