High-performance perovskite solar cells by incorporating a ZnGa2O4:Eu3+ nanophosphor in the mesoporous TiO2 layer

ZnGa 2 O 4 :Eu 3+ nanophosphor was synthesized through a hydrothermal method and used as an effective light down-shifting/converting material in mesoporous TiO 2 layer of perovskite solar cells (PSCs). The nanophosphor can convert the high energy incident photon into the photon(s) with lower energy, which can excite CH 3 NH 3 PbI 3 to generate more photo generated electron–hole pairs, and thus promote the incident light use ratio and increase the power conversion efficiency (PCE) of PSCs. After the incorporation of suitable amount of ZnGa 2 O 4 :Eu 3+ into PSCs, the cell PCE is increased to 13.80% with a photocurrent density of 23.68   mA   cm − 2 and a highest PCE of 14.34% with a photocurrent density of 25.02   mA   cm −2 is achieved, much higher than those of the cell without ZnGa 2 O 4 :Eu 3+ (PCE of 10.67% and photocurrent density of 20.2   mA   cm −2 ). The enhanced photovoltaic performance by incorporating the nanophosphor into PSCs should be ascribed to the increased incident light use ratio and improved exciton generation rate.