11:00 AM - 11:15 AM
▲ [23a-B103-8] Indent free vapor assisted surface passivation strategy towards tin halide perovskite solar cells
Keywords:Tin halide perovskite
Tin (Sn) in halide perovskite is proposed as an important alternative, owing to the suitable bandgap close to the Shockley-Queisser limit, high charge carrier mobility, small exciton binding energy, and high carrier mobility. However, the highest reported power conversion efficiency based on tin halide perovskites is still lower than Pb based one. Liquid surface passivation on the perovskite layer is commonly used to decrease these defects. In the case of tin perovskite solar cells, the liquid passivation improved open-circuit voltage Voc. However, this decreased the short-circuit current density Jsc. We found that this Jsc loss is brought about by the thickness loss after the liquid passivation, because tin perovskite layers are partially soluble in common solvents and the calculated impact pressure was up to 155.4 kPa. Here we introduce a new vapor passivation including solvent and passivation molecules, and report efficiency enhancement without decreasing Jsc. The vapor-passivated film showed longer time-resolved photoluminescence decay, smoother morphology, and lower defect densities. Most importantly, the vapor passivation method significantly enhanced the efficiency from 9.41 to 11.29% with Jsc increased from 22.82 to 24.05 mA ·cm-2. On the contrary, the corresponding liquid passivation method gave the efficiency of 10.90% with decreased Jsc from 22.82 to 22.38 mA ·cm-2.A commonly used and simple indent free surface passivation strategy is proposed to enhance the efficiency and the stability of PKSCs.