Effect of Bidentate Ligand Additive in Tin Perovskite Solar Cells

Tin- perovskite solar cell (Sn-PSC) is limited by their poor stability arising from facile tin oxidation and uncontrolled film growth. Here, we introduced a multifunctional bidentate ligand, formohydrazide (FHZ) as an additive into FASnI3 perovskite film. This additive is found to be effective for the control of Sn-oxidation and forms pin-hole free film morphology. The Sn-PSCs with FHZ additive enhanced the device efficiency from 9.93% (for control Sn-HaP) to 13.14 % (for device with FHZ additive) with higher reproducibility and superior device stability. The device analysis suggests that the hydrazide additive significantly passivates the bulk and surface defect in the Sn-PSCs. This report gives insights into the film growth properties, device photo-physics, and defect analysis correlating with device performance and device stability.

锡基钙钛矿太阳能电池（Sn-PSC）因其易受锡氧化和不受控制的薄膜生长所导致的稳定性不佳而受限。本研究中，我们引入了一种多功能双齿配体——甲叉肼（FHZ），将其作为添加剂加入FASnI3钙钛矿薄膜中。研究发现，此添加剂对于控制锡氧化及形成无针孔薄膜形态具有显著效果。含有FHZ添加剂的Sn-PSCs将器件效率从9.93%（对照Sn-HaP）提升至13.14%（FHZ添加剂器件），同时提高了重现性和器件的稳定性。器件分析表明，肼类添加剂显著钝化了Sn-PSCs中的体相和表面缺陷。本报告揭示了薄膜生长特性、器件光物理性质以及与器件性能和稳定性相关的缺陷分析。