Thermal Effects on Carrier Dynamics in Two-Dimensional Dion–Jacobson Hybrid Perovskites

Two-dimensional (2D) perovskites have received a lot of attention due to their more stable properties than three-dimensional perovskites. Here, temperature-dependent UV–vis absorption and transient absorption (TA) measurements were performed for the 2D Dion–Jacobson phase organic–inorganic hybrid perovskite (4AMP)PbI4 (4AMP = 4-(aminomethyl)piperidinium). At 80–295 K, the exciton absorption peak red-shifts with increasing temperature, indicating that the electron–phonon interaction dominates in (4AMP)PbI4. The TA spectra show that with the decrease of temperature, the lattice shrinks and the transient Stark effect is enhanced. By comparing the dynamics, we find that the carrier relaxation lifetime becomes longer with the increase of temperature. On the one hand, the free carriers increase in proportion due to the generation of exciton-polarons. On the other hand, on account of the thermally assisted Rashba effect, the carrier recombination is slowed down by the shift of band extrema in k-space. This study reveals the effect of temperature on carrier behavior in (4AMP)PbI4, which is of great significance for its applications in optoelectronic devices.