Fig. 5. (a) The pressure-driven bandgap evolution of MAPbI₃ with both experimentally measured data and theoretically calculated values. (b) The pressure dependence of the mean carrier lifetime τ for both single-crystalline and polycrystalline MAPbI₃ with peak τ values at 0.3 GPa. The inset displays the normalized results. (c) Schematic illustrations of the band edge shifts and carrier-lifetime prolongation under mild pressure. As the bandgap narrows, the subgap approaches the VBM and makes the trap state shallower, contributing to the larger carrier lifetime. (d) The pressure-induced changes in the bandgap and carrier lifetime of MAPbBr₃. Reproduced with permission from ref. 49.