Effect of the conduction band offset on interfacial recombination behavior of the planar perovskite solar cells

In planar-structure perovskite solar cells (PSCs), a spike structure is formed between the perovskites and the electron selective layer (ESL), i.e., the energy level of the conduction band of the ESL is higher than that of the perovskite absorber. This spike structure can lead to less photovoltage loss for the PSCs while maintaining high electron injection, which results in a higher open-circuit voltage and a greater short-circuit current, as well as a higher efficiency for planar PSCs.213