No abstract

Organic-inorganic lead halide perovskite semiconductors have recently reignited the prospect of a tunable, solution-processed diode laser, which has the potential to impact a wide range of optoelectronic applications. Here, we demonstrate a metal-clad, second-order distributed feedback methylammonium lead iodide perovskite laser that marks a significant step toward this goal. Optically pumping this device with an InGaN diode laser at low temperature, we achieve lasing above a threshold pump intensity of 5 kW/cm(2) for durations up to ∼25 ns at repetition rates exceeding 2 MHz. We show that the lasing duration is not limited by thermal runaway and propose instead that lasing ceases under continuous pumping due to a photoinduced structural change in the perovskite that reduces the gain on a submicrosecond time scale. Our results indicate that the architecture demonstrated here could provide the foundation for electrically pumped lasing with a threshold current density Jth < 5 kA/cm(2) under sub-20 ns pulsed drive.

Hybrid perovskite semiconductors represent a promising platform for color-tunable light emitting diodes (LEDs) and lasers; however, the behavior of these materials under the intense electrical excitation required for electrically-pumped lasing remains unexplored. Here, we investigate methylammonium lead iodide-based perovskite LEDs under short pulsed drive at current densities up to 620 A cm−2. At low current density (J < 10 A cm−2), we find that the external quantum efficiency (EQE) depends strongly on the time-averaged history of the pulse train and show that this curiosity is associated with slow ion movement that changes the internal field distribution and trap density in the device. The impact of ions is less pronounced in the high current density regime (J > 10 A cm−2), where EQE roll-off is dominated by a combination of Joule heating and charge imbalance yet shows no evidence of Auger loss, suggesting that operation at kA cm−2 current densities relevant for a laser diode should be within reach.

a few hundred ns following pump turn-on. The origin of this behavior, termed lasing death, is not well understood and has led to speculation on a variety of potential causes ranging from simple heating [4] to accumulation of photogenerated quenching species and photoenhanced dielectric screening. [5] Resolving this question is important, both for its relevance to achieving a laser diode and because room temperature cw lasing may be practically useful in its own right for diode-pumped solid-state laser applications.Here, we investigate the origin of lasing death in the prototypical perovskite semiconductor methylammonium lead iodide (MAPbI 3 ) and find that it stems from a combination of local heating and photoinduced defects that increase the rate of nonradiative recombination. Transient lasing and photoluminescence (PL) measurements show that, within 0.5 µs of pump turn-on, the temperature of distributed feedback (DFB) MAPbI 3 lasers on sapphire increases by ≈30 K and the Shockley-Read-Hall rate coefficient increases roughly fivefold under cw-relevant pump intensities of ≈20 kW cm −2 . The role of each effect is quantitatively understood using a coupled thermal and laser rate equation model that is subsequently used to predict what improvements in heat extraction and threshold reduction are required to achieve cw operation at room temperature.

No abstract