Synergistic Co-Passivation via Ultrasmall Molecules for Efficient and Stable Perovskite Solar Cells

Engineering notes

Engineering notes will be added by the Power for Solar editorial team.

Chinese explanation / 中文解读

中文解读待补充：本站会优先为光伏效率、钙钛矿太阳能电池、储能技术、太阳能热利用、BIPV、并网技术等高价值论文补充中文说明。

Original abstract

Defect passivation is one feasible and effective approach to minimize the charge recombination of perovskite solar cells (PSCs). However, the efficacy of conventional defect passivation using Lewis base-functionalized molecules is limited due to weak bonding and large space steric hindrance. Herein, we propose a molecular engineering approach employing ultrasmall-sized potassium diformate and potassium phosphate to synergistically passivate defects at the SnO 2 /perovskite buried interface. It is found that the C═O and P═O groups effectively passivate interfacial traps, reducing trap density by ∼50% relative to the control sample. The co-modification also lowers the surface energy of SnO 2 layers, promoting the growth of perovskite grains with an average grain size increased from 780 to 1370 nm. Moreover, thermally diffused K + ions can inhibit ion migration in the perovskite lattice, thereby suppressing the hysteresis effect. According to these advantages, the optimized devices achieve a champion power conversion efficiency of 24.42% (vs 22.64% for the pristine SnO 2 -based counterpart). The unencapsulated co-passivated PSCs retain 92% of their initial efficiency after 2100 h under ambient conditions, substantially outperforming the control devices (74% retention).

Links and sources

Comments