Well-in-Well Active Region Based III-Nitride Colour-Tunable LED

Abstract

A well-in-well structure is proposed in the multiple quantum well (MQW) based active region of the III-Nitride based light emitting diode (LED) in order to achieve tunable emission by varying the applied bias. It has been found that the composite rectangular well structure takes a complex triangular quantum well structure under applied bias and the energy of the n-th electronic level in the QW increases with increasing bias resulting in blue-shift of the emission wavelength with increasing bias. This principle enabled a simulation study that results in a colour tunable model for the III-N based LEDs. It has been found that around 2.7V of applied bias the LED emits in red (~636 nm) with an internal quantum efficiency (IQE) of ~30% whereas at 3.4-3.6V of applied voltage it emits at green (~556 nm) with a promising ~75% of IQE. Hence the proposed structure is promising for realizing colour tunable LED by varying the applied bias. As a result, all the required colours, i.e., RGB will be available on a single material (III-Nitrides) platform for display applications. © 2023 IEEE.