Nanocrystal-based microcavity light-emitting devices operating in the telecommunication wavelength range

Abstract

Highly luminescent colloidally prepared HgTe nanocrystals (NCs) are used to fabricate microcavity light-emitting devices operating around 1.5μm. They consist of a Bragg interference mirror from standard optical materials deposited on glass substrates, an active layer embedding the nanocrystals, and a metallic top mirror. These devices give highly directional narrow single-mode emission with a beam divergence below 3° and a spectral width smaller by a factor of 8 than that of a NC reference sample. The emission wavelength can be tuned between 1.4 and 1.75μm by changing the cavity length and thus, the cavity finesse. The influence of the latter on output power and beam divergence is discussed. Furthermore, operation up to 75 °C is demonstrated without degradation of the NCs, which is promising for potential applications.