A GaAs polariton light-emitting diode operating near room temperature

Solid-sate physics: Practical polaritronics A tight control over light–matter interactions can be achieved at a nanometre scale in a semiconductor microcavity. The strong coupling between excitons in the semiconductor material and photons resonating in the cavity gives rise to new hybrid half-light/half-matter quasiparticles called polaritons. The unique properties of polaritons, giving rise to exotic lasing and quantum condensation effects, have the potential to spawn a new generation of particle emitters and semiconductor lasers. Polariton lasing and nonlinearities have been demonstrated in optical experiments, but it would be of considerable technological interest to demonstrate electrically driven polariton light-emitting devices. This has now been accomplished in a gallium arsenide diode that emits light directly from polariton states held at the relatively high temperature of 235 K (−38° C). The authors believe that the findings represent a significant step towards the realization of a new class of ultra-efficient polaritronic devices with unprecedented characteristics.