Due to their improved charge transfer and great environmental stability, 2D Dion-Jacobson (DJ) perovskites have recently received a lot of attention.
Unfortunately, due to the scarcity of high-quality single crystals for precise measurements, their fundamental optoelectronic capabilities are mainly unknown. Here, a reactive, low-temperature-gradient crystallization method is created using 1,4-butanediammonium as a short-chain insulating spacer to generate high-quality 2D perovskite single crystal (BDAPbI4). It is discovered that the BDAPbI4 single crystal exhibits a direct bandgap with effective charge collection (μτ = 1.45 × 10−3 cm2 V−1). The BDAPbI4 single crystal in particular exhibits the expected high ion migration activation energy (0.88 eV).
