Polarization Modulation at Last Quantum Barrier for High Efficiency AlGaN-Based UV LED

The performance of AlGaN-based light-emitting diodes (LEDs) emitting at UVA–UVC regions can be severely compromised due to the polarization difference (ΔP) between last quantum barrier (LQB) and electron blocking layer (EBL). In this work, different situations bandgap (ΔE g ) ΔP InAlN/AlGaN AlGaN/AlGaN heterojunctions fully strained on GaN AlN substrates are discussed. It shows that could produce positive or negative sheet charges heterointerface under ΔE >0, which not realized by conventional heterojunctions. To demonstrate utilize feature, polarization-modulated InAlN LQBs with 0.14–0.16 indium compositions 320 nm UVB LEDs designed investigated. is observed replace AlGaN LQB improve confinement hole injection affecting effective heights. By modulating LQB/EBL using InAlN, proposed UV LED has a 32% enhancement in internal efficiency lower droop (from 16.9% 0.7%) compared one without modulation. operation voltage same current also significantly decreases. improvement optical output power wall plug 60 mA structures near 90% 100%, respectively. This study provides novel highly methodology for development high LEDs.