High-efficiency 1.3 μm InGaAs/GaAs quantum-dot microcavity light-emitting diodes grown by metalorganic chemical vapor deposition

摘要

We investigate the optical properties of quantum-dot (QD) microcavity light-emitting diodes (MCLED) operating at 1.3 μm at room temperature. The active medium consists of a single layer of InGaAs quantum dots, directly grown in a GaAs matrix by metalorganic chemical vapor deposition. Electrical injected QD MCLEDs were fabricated by exploiting a hybrid technology, which employs epitaxial and oxide-based mirrors. Such technology allows us to preserve the QD properties and leads to a wider optical bandwidth of the hybrid top distributed Bragg reflector with respect to the fully epitaxial mirror, resulting in photon recycling of the overall QDs spectrum, thus improving the efficiency of the device. The devices exhibit bright electroluminescence peaked at 1.29 μm, with a full width at half maximum of 10 meV. The room-temperature external quantum efficiency of such devices is 0.52%, higher than that reported in the literature for QD MCLEDs operating at 1.3 μm at room temperature.