Hybrid material for the fabrication of electron transport layer in perovskite solar cell

Perovskite solar cell technologies require better control carrier mobility in the device, as they move toward their theoretical power conversion efficiency. Perovskite, as an excellent light absorber, can harvest sunlight up to 800 nm moreover, act as excellent transporter of electrons as well as holes. Quite large ambipolar carrier diffusion lengths enable perovskites to be directly incorporated between a p-type and n-type buffer, make modest planar p-i-n or n-i-p structure with outstanding performances. Careful choices of materials and controlled formation of perovskite layer, supported charge injection into the carrier transport layers, suppressed charge recombination in the absorber and maintained good carrier extraction at the electrodes play a key role in perovskite solar cell. This review is a summary of various inorganic electron transport layer (ETL) and organic ETL systems of Perovskite solar cells. The electron transport mechanism and design of various ETL materials have been discussed to enhance the overall device performance. Technical issues that increase the stability and efficiency of the device with respect to materials have been generalized.