Improved Performance and Efficiency of AlGaN‐Based Deep‐Ultraviolet Light‐Emitting Diode with Linearly Graded Quantum Well Structure

AlGaN‐based deep‐ultraviolet (DUV) light‐emitting diodes (LEDs) hold great promise for a wide range of applications, including water sterilization, biochemical sensing, and UV curing. However, their efficiency is fundamentally limited by the quantum‐confined Stark effect (QCSE) originating from strong spontaneous and piezoelectric polarization fields in c‐plane quantum wells (QWs). These internal fields induce pronounced band bending and spatial separation of electron and hole wavefunctions. In this work, a multiple quantum well (MQW) design with a linearly graded‐aluminum composition is introduced along the [0001] direction of the QWs. The grading suppresses polarization discontinuities at quantum barrier (QB)/quantum well (QW) interfaces, reducing interface‐bound charges, and simultaneously generates distributed bulk polarization charges that create a reverse internal electric field. This counter‐field mitigates QCSE, resulting in flattened band profiles and improved wavefunction overlap. Technology computer‐aided design (TCAD) simulations using the SILVACO Advanced Technology Large‐Area Simulator (ATLAS) platform show an increase in electron–hole overlap from 92.45% to 98.26%, a 44.16% enhancement in light output power, a 63.6% reduction in internal electric field, and a 0.7 V decrease in forward voltage. The novelty of this work lies in applying in‐well linear compositional grading as a polarization‐field engineering technique for AlGaN QWs, enabling simultaneous enhancement of optical and electrical performance.In this work, a practical, scalable, and simulation‐verified pathway toward high‐efficiency AlGaN‐based DUV LEDs is reported.