Factors that Limit Continuous‐Wave Lasing in Hybrid Perovskite Semiconductors

Abstract Metal halide perovskites are a promising platform for solution‐processed semiconductor lasers but have so far only achieved continuous‐wave (cw) operation at low temperature. Here, the origin of this limitation is investigated in prototypical methylammonium lead iodide (MAPbI₃) distributed feedback (DFB) lasers and is found to stem from a combination of pump‐induced heating and the accumulation of photoinduced defects. A temperature rise of more than 30 K in the first few hundred ns following pump turn‐on is observed, which leads to a dynamic increase in threshold owing to the strong temperature dependence of stimulated emission in MAPbI₃ thin films. In parallel, it is found that the Shockley–Read–Hall rate coefficient increases by an order of magnitude on a similar timescale, suppressing the carrier density generated by the pump. The combined impact of both effects is understood using a comprehensive model that quantitatively explains the duration of lasing as a function of pump intensity and predicts that the threshold of current DFB lasers must be decreased by an order of magnitude to achieve cw operation at room temperature.