Thick Sn-Pb Perovskite Films with 2D/3D Structure for High Performance Solar Cells

Tin based perovskites have drawn much attention for narrow bandgap and eco-friendliness. In our previous work, high quality Sn-Pb perovskite films with vertically aligned large grains and high crystallinity were achieved on a hydrophobic hole transport layer by a two-step processing method. However, it remains a challenge to achieve thick films which are required to enhance light absorption especially in near-infrared region, and thus the performance is limited by the low short-circuit current due to the thin films. Here, a 2D/3D structure was applied to obtain high quality thick Sn-Pb perovskite films and finally a PCE of 15.7% was obtained.