Analysis of ultrafast carrier dynamics and steady-state reflectivity on lattice expansion in metal halide perovskite during continuous illumination

Lattice expansion in hybrid halide perovskite directly affects its photoelectric properties and the stability of perovskite-based optoelectronic devices, which was certified also to closely connect with relevant inducing mechanisms. From the perspective of carrier relaxation dynamics and dielectric properties, we report the results employing ultrafast time-resolved transient and steady-state reflectivity technology to diagnose the lattice expansion occurring in bulk hybrid perovskite MAPbI(3) during continuous illumination and directly heating, respectively. Upon continuous illumination at a constant temperature, there were no evident structural changes in MAPbI(3), but in the condition of naturally temperature changes, the lattice expansion can be induced by continuous light illumination and is consistent with the effect of heat-inducted expansion. The present results are based on the physical mechanism that the change of the electronic structure caused by lattice expansion leads to the change of the dielectric properties in MAPbI(3) and sequentially to the change of light reflectivity.

Automated summary

The lattice expansion in hybrid halide perovskite has a direct impact on its photoelectric properties and the stability of perovskite-based optoelectronic devices. This study investigates the lattice expansion in bulk hybrid perovskite MAPbI(3) under continuous illumination and direct heating using ultrafast time-resolved transient and steady-state reflectivity technology. The results suggest that continuous light illumination can induce lattice expansion in the presence of natural temperature changes, which is consistent with the effect of heat-induced expansion.