Effect of TiCl4 Treatment on Different TiO2 Blocking Layer Deposition Methods

Organolead halid perovskite CH 3 NH 3 PbI 3 solar cells with all-mesoporous device structure were fabricated with TiO 2 blocking layer created by two different methods. Three groups of devices were tested. The TiO 2 blocking layer of group 1 was spin-coated with conventional method, while that of groups 2 and 3 was grown by magnetron sputtering of metallic Ti and followed thermal oxidation. Different durations (0, 30, 45, and 60 minutes) of TiCl 4 treatment were used during fabrication to study how the performance of each group of solar cells was affected. For all groups of samples, it was obvious that treated samples had much better I-V characteristics that non-treated, with up to 50% improvement in PCE. The difference in the performance improvement was investigated.