The finest Hole Transport Layer (HTL) with extraordinary optical and electrical properties are significantly influenced the Power Conversion Efficiency (PCE) of the photovoltaic device. Inorganic hole transport materials exhibit better performance than organic hole transport materials. Herein, we demonstrated that optoelectronic properties of inorganic materials of NiO doped with Cu as Hole Transport Layer (HTL) for Lead free Bismuth halide perovskite solar cell. Solution process method of sol – gel was used to synthesize p-type NiO doped with Cu and yield nano particles of high quality. Cu + doped into Ni2+ sites has improved the crystallization of nanoparticles, carrier mobility and carrier electric properties. Results of the study revealed that the Enhancement of electrical conductivity of about 2 % is obtained for NiO doped with Cu which is ∼1.287 × 10−02 compared to the pristine NiO which is ∼2.655 × 10−03.