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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 cavities2–4 and predesigned5,6 or postprocessed microstructures7,8
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 architectures12–15 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.