Demonstration of near‐size independent EQE for 368 nm UV micro‐LEDs

Abstract

UV‐ranged micro‐LEDs are being explored for numerous applications due to their high stability and power efficiency. However, previous reports have shown reduced EQE and increased leakage current due to the increase in surface‐to‐volume ratio with a decrease in the micro‐LED size. In this work, we studied the size‐related performance for UV‐A micro‐LEDs, ranging from 8 × 8 µm2 to 100 × 100 µm2. These devices exhibited reduced leakage current with the implementation of ALD based sidewall passivation. A systematic EQE comparison was performed with minimal leakage current and obtained a size‐independent on‐wafer EQE of around 5.5%. Smaller sized devices experimentally showed enhanced EQE at high current density due to their improved heat dissipation capabilities. To the best of authors’ knowledge, this is the highest reported on‐wafer EQE demonstrated in < 10 µm dimensioned 368 nm UV LEDs.This article is protected by copyright. All rights reserved.