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

Highly luminescent colloidally prepared HgTe nanocrystals (NCs) are used to fabricate microcavity light-emitting devices operating around 1.5 μ m . 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 1.75 μ m 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.