Non-epitaxial perovskite polariton laser diode operating under direct current

Reaching lasing in electrically pumped microdevices based on solution-processed semiconductors poses a substantial scientific and technological challenge. Halide perovskites offer a promising platform for electrical injection¹, as their optically excited single-crystal cavities^2-4 and predesigned^5,6 or postprocessed microstructures^7,8 have exhibited low lasing threshold. Indirect electrical pumping of a dual-cavity perovskite laser was recently obtained⁹, using a well-established technological concept of embedding a high-luminosity light-emitting diode (LED) with a high-gain medium into an integrated device¹⁰. Direct charge-carrier injection into a perovskite LED excited by auxiliary short, optical pulses resulted in amplified spontaneous emission (ASE)¹¹. Other efforts for rational engineering of architectures^12-15 that allow for high charge-carrier density are still to demonstrate lasing. Here we develop a new strategy for achieving direct electrical pumping of a perovskite laser. We integrate a solution-grown CsPbBr₃ microplate with chemically inert single-walled carbon nanotube (SWCNT) electrodes and embed them into an optical microcavity. By cooling the microdevice down to 8 K at a constant current, a perovskite p-i-n diode is formed that facilitates a balanced carrier injection at high current densities. The perovskite microcavity diode operates in the strong coupling regime, exhibiting polariton lasing under a direct current of 65 μA.