Effect of indium molar content in Al_xIn_yGa_(1-x–y)N/Al_aGa_bN orderly quantized integrated quantum barrier for highly efficient droop free UV-C LEDs

This article proposes a new Ultra-Violet (UV)-C Light emitting Diode (LED) structure based on orderly aligned Quaternary Nitride alloy based specially-designed quantized quantum barrier. In this article, we theoretically investigate the performance such as internal quantum efficiency (IQE), efficiency droop etc. of proposed structure and also compare it with the reference UV-C LED structure. In this proposed structure, there is no sudden potential barrier as in case of reference structure because of the strain compensation provided by the quantized periodic Superlattice-Al_xIn_yGa_(1-x–y)N/ Al_aGa_bN quantum barrier. Active region epilayer crystal orientation balanced by introducing ‘In' molar content in alternate sub-layers of quantum barrier (QB). This allows for stronger carrier confinement in the active region, which enhances IQE to 72% from 32% (reference structure) and reduction in efficiency droop from 11% to 0.05% at current density of 200 A-cm⁻². The variation in the density of states (DOS) for carrier allocation due to strain balance in the quantum barrier compared to the quantum wells (QW) is responsible for the significant increase in the electro-optical efficiency of the light emitting device.