Mixed halide perovskite light emitting solar cell

Abstract

We demonstrate that the halide perovskite planar solar cells with the architecture of ITO/PEDOT:PSS/Perovskite/PCBM/LiF/Al show a switchable dual operation of descent photovoltaic and quite bright electroluminescence in visible range. In our experiments, the active layer is made of a mixed halide perovskite (MAPbBr2I) and the device is properly cycled upon light and bias exposure. We argue that this curious effect of switchable double functionality between solar cell and light-emitting device in one architecture is caused by photoinduced segregation in the perovskite. It is shown that the bright red electroluminescence at low voltage of ∼ 2 (3) eV appears only after cycling the device in PV regime. On the other hand, electroluminescence operation also effects the following PV mode. This effect is caused by redistribution of photoactivated ions I-/Br- and their vacancies during photoexcitation in PV regime.