Proceedings of Perovskite Thin Film Photovoltaics (ABXPV)
Publication date: 14th December 2015
Transient optoelectronic techniques such as transient photovoltage (TPV) have been widely used to study device performance, especially the open-circuit voltage, of a range of thin film photovoltaic technologies. Such techniques have the potential to help better understand the recombination process which determine device performance in perovskite based photovoltaics. Our recent work on the planar structure, which includes PCBM as an electron extracting layer, shows negligible hysteresis at room temperature, thus providing a stable system allowing for the use of transient techniques such as TPV. The Br content of a MAPX (CH3NH3Pb(I1-xBrx)3) perovskite active layer was increased, leading to an increase in the device open-circuit voltage by up to 170 mV. This increase in VOC was found to be primarily from an energetic increase in bandgap; however, this was somewhat limited by a competing increase in recombination rate. Finally, the device voltage could be reproduced from the measurements of recombination flux, for a wide range of light intensities.