A PCBM-Modified TiO₂ Blocking Layer towards Efficient Perovskite Solar Cells

Abstract

Organometal halide perovskite as a promising absorber in solar cells has caught tremendous attention in the past few years. Herein, a hydrophobic PCBM layer was introduced into planar heterojunction perovskite solar cells to form the TiO 2 /PCBM double blocking layer. The bilayer structure assures the formation of a dense, smooth, and pinhole-free blocking layer. And the PCBM layer can also be in favor of larger grain size perovskite film and further passivate the TiO 2 blocking layer. Scanning electron microscope, atomic force microscope, and X-ray diffraction (XRD) results suggest the formation of a uniform and compact CH 3 NH 3 PbI 3− x Cl x perovskite layer on the PCBM-modified TiO 2 blocking layer. The solar cell has reached a PCE up to 16.37%, which is greatly larger than the control device with a PCE of 10.81%.