Buried Interface evolution of 2D/3D heterojunction inverted perovskites solar cells

The instability of perovskite interfaces caused by interfacial defects and heterojunction evolution hinders the realization of long-term stable inverse perovskite solar cells (IPSCs). This work reports a strategy for the study of heterojunction evolution, the effects of buried interface and carrier dynamics on the stability of perovskite films and devices in 2D/3D heterojunctions. The emphasis is on selecting PEA ammonium salts of different halogens as the buried interface of perovskites and constructing heterojunction structures at the three-dimensional perovskite lower interface. By placing constructed heterojunction perovskite films on a constant temperature hotplate at 60 °C for long-term aging treatment, the changes in carrier behavior of heterojunction films were investigated. By exploring the evolution law of 2D perovskite and observing the buried interface, there are many PbI₂ crystals in the perovskite grain boundary of initial perovskite thin film buried interface, and the number of lead iodide (PbI₂) crystals decreases significantly after 15 days of aging. This study perfects the scientific theoretical system of the buried interface of mixed-dimensional semiconductor perovskite devices and lays a key technical foundation for the development of high-efficiency and long-life perovskite optoelectronic devices.