Electroluminescence from single nanowires by tunnel injection: an experimental study

TL;DR

This study demonstrates ultraviolet electroluminescence from single gallium nitride nanowires via tunnel injection, challenging the conventional p-n junction model and providing insights into nanowire-based light-emitting diodes.

Contribution

It introduces a hybrid nanowire LED structure and explains electroluminescence through tunnel injection, deviating from traditional p-n junction assumptions.

Findings

Ultraviolet light emitted under both bias polarities.

Tunnel injection explains electroluminescence behavior.

Standard p-n junction model is not applicable.

Abstract

We present a hybrid light-emitting diode structure composed of an n-type gallium nitride nanowire on a p-type silicon substrate in which current is injected along the length of the nanowire. The device emits ultraviolet light under both bias polarities. Tunnel-injection of holes from the p-type substrate (under forward bias) and from the metal (under reverse bias) through thin native oxide barriers consistently explains the observed electroluminescence behaviour. This work shows that the standard p-n junction model is generally not applicable to this kind of device structure.