Effects of copper addition on photovoltaic properties of perovskite CH3NH3PbI3−xClxsolar cells

This paper presents the effects of copper (Cu) addition on the photovoltaic properties of perovskite CH 3 NH 3 PbI 3− x Cl x solar cells. The effects were investigated by measuring the current density–voltage ( J – V ) characteristics and external quantum efficiency. In the present work, CuBr and CuBr 2 were used as additives. The photovoltaic properties of the CuBr‐added CH 3 NH 3 PbI 3− x Cl x devices showed a clear improvement. Structural and optical properties of the CuBr‐ and CuBr 2 ‐added CH 3 NH 3 PbI 3− x Cl x films were also investigated. Based on the present results, the changes in the photovoltaic properties were discussed.