Factors that Limit Continuous-Wave Lasing in Hybrid Perovskite Semiconductors

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 (MAPbI(3)) 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 MAPbI(3) 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.