A PCBM-assisted perovskite growth process to fabricate high efficiency semitransparent solar cells

Developing highly efficient perovskite solar cells in a simple and rapid fashion will open the window for their potential commercialization. Semi-transparent devices are of great interest due to their attractive application in building integrated photovoltaics (BIPVs). In this study, efficient perovskite solar cells with good transparency in the visible wavelength range have been developed by a facile and low-temperature PCBM-assisted perovskite growth method. This method results in the formation of a perovskite-PCBM hybrid material at the grain boundaries which is observed by EELS mapping and confirmed by steady-state photoluminescence (PL) spectroscopy, transient photocurrent (TP) measurements and X-ray photoelectron spectroscopy (XPS). The PCBM-assisted perovskite growth method involves fewer steps and therefore is less expensive and time consuming than other similar methods. The semitransparent solar cells developed using this method exhibited power conversion efficiency (PCE) ranging from 12% to 4% depending on the average visible transmittance (AVT) ranging from 3% to 35%. The as-fabricated semitransparent perovskite solar cell with an active layer thickness of only about 150 nm, which is only less than half the active layer thickness of a typical perovskite solar cell, provided a PCE as high as 9.1% with an AVT of 18% and more than 12% with an AVT of 3%.