Optically Pumped Lasing from Hybrid Perovskite Light-Emitting Diodes

Electrically pumped lasing from hybrid organic–inorganic metal-halide perovskite semiconductors could lead to nonepitaxial diode lasers that are tunable throughout the visible and near-infrared spectrum; however, a viable laser diode architecture has not been demonstrated to date. Here, an important step toward this goal is achieved by demonstrating two distinct distributed feedback light-emitting diode architectures that achieve low threshold, optically pumped lasing. Bottom- and top-emitting perovskite light-emitting diodes are fabricated on glass and Si substrates, respectively, using a polydimethylsiloxane stamp in the latter case to nanoimprint a second-order distributed feedback grating directly into the methylammonium lead iodide active layer. The devices exhibit room temperature thresholds as low as ≈6 µJ cm⁻², a peak external quantum efficiency of ≈0.1%, and a maximum current density of ≈2 A cm⁻² that is presently limited by degradation associated with excessive leakage current. In this low current regime, electrical injection does not adversely affect the optical pump threshold, leading to a projected threshold current density of ≈2 kA cm⁻². Operation at low temperature can significantly decrease this threshold, but must overcome extrinsic carrier freeze-out in the doped organic transport layers to maintain a reasonable drive voltage.