Exploring charge behavior at the terminal surface and charge separation interface of organo-lead perovskite using in situ surface photovoltage spectroscopy.

The differences in charge separation and transfer processes between the 'non-charge-separation' terminal surface and perovskite/FTO 'charge-separation' interface have been studied using comparative lock-in amplifier-based SPV signals. The SPV phase vector model delves deeper into the direction of charge separation and trapping at the perovskite surface/interface.

Charge transport dynamics of a C6H4NH2CuBr2I/TiO2 heterojunction in aqueous solution under reverse bias.

The photocurrent output of the C6H4NH2CuBr2I/TiO2 heterojunction photoelectrode in an aqueous solution is super stable even after 30 000 s. However, the photocurrent is extremely weak. Intensity-modulated photocurrent spectroscopy revealed that the electron transfer in the C6H4NH2CuBr2I/TiO2 photoelectrode without bias is not sufficiently fast to compete with the charge recombination process due to the short diffusion length (∼23 nm), resulting in a low photocurrent. The charge separation and charge transfer efficiency in the bulk of C6H4NH2CuBr2I could be significantly improved under a small reverse electric field (Er), resulting in an enhanced photocurrent.