High efficiency quantum dot microcavity light emitting device operating at 1.3 μm

In this work we report on the optical properties of electrical injected microcavity light emitting diodes emitting at 1.3 μm at room temperature. The active medium consists of a single layer of reduced strain quantum dots, directly grown in a GaAs matrix by metalorganic chemical vapour deposition (MOCVD). Based on this method, two different fabrication approaches have been developed: one based on a fully epitaxial structure and one based on a hybrid structure, matching semiconductor epitaxial and dielectric mirrors. The device based on the hybrid technology, less invasive for the quantum dot optical properties, exhibits, at room temperature, high external quantum efficiency. The effect of the selective oxidation on the top mirror is also investigated and improved device performance is found. These results represent a promising way for the realisation of high performance QD VCSEL structures.