Nanowire-based telecom-band light-emitting diodes with efficient light extraction

Semiconductor nanowires grown by the gold-free, self-catalyzed, vapor-liquid-solid approach have great potential for realizing monolithically integrable light sources in the telecom band towards integrated optoelectronic circuits. However, light-emitting diodes based on such nanowires operating in the telecom band range remain challenging to achieve, due to difficulties in growing nanowires with suitable materials to cover the telecom band range, their geometrical shape to enhance light extraction efficiency, and their junction structure to suppress current leakage. Here we report telecom-band light-emitting diodes operating at room temperature using InP/InAs axial-heterostructure nanowires grown by self-catalyzed vapor-liquid-solid mode with efficient light extraction. Conically tapered nanowire structures with a single axial junction structure are advantageous for increasing light extraction and carrier injection efficiencies. We realize the structure by making use of a distinctive growth phenomenon in self-catalyzed vapor-liquid-solid growth; i.e. continuously tunable size of catalyst particles during growth.