Carrier Transport in 2D Hybrid Organic-Inorganic Perovskites: The Role of Spacer Molecules

Two-dimensional organic-inorganic hybrid perovskites (2D HOIPs) have been widely used for various optoelectronics applications owing to their excellent photoelectric properties. However, the selection of organic spacer cations is mostly qualitative without quantitative guidance. Meanwhile, the fundamental mechanism of the carrier transport across the organic spacer layer is still unclear. Here, by using the first-principles nonadiabatic molecular dynamics (NAMD) method, we have studied the transport process of excited carriers between 2D HOIPs separated by a spacer cation layer in real time at atomic levels. We find that the excited electrons and holes can transfer from single-inorganic-layer 2D HOIP to bi-inorganic-layer 2D HOIP on a subpicosecond to picosecond scale. Moreover, we have developed a new method to capture the electron-hole interaction in the frame of NAMD. This work provides a promising direction to design new materials toward high-performance optoelectronics.