Size-Dependent Characteristics of InGaN-Based Blue and Green Micro-Light-Emitting Diodes

This study focuses on investigating the size-dependent characteristics (chip diameter: 100-10 mu m) of InGaN-based blue and green micro-light-emitting diodes (mu LEDs) with respect to their electrical and optical properties. The LED's epistructure is grown using the metal-organic chemical vapor deposition technique, preceded by simulation and optimization using SiLENSe LED simulator. The cross-sectional transmission electron microscopy study confirms the epistructure. The Photoluminescence mapping of the epistructure reveals that the blue emission is at 461 nm (full width at half maximum [FWHM] approximate to 15.5 nm) and the green emission is at 510 nm (FWHM approximate to 17.5 nm). The study analyzes the size-dependent external quantum efficiency (EQE), optical power, and peak wavelength shift between blue and green mu LEDs. The electroluminescence (EL) study reveals that the redshift of the EL peak wavelength of mu LEDs is attributed to the release of strain at reduced chip sizes. The size-dependent EQE study shows a reduction of EQE with shrunken chip size, attributed to the increase of nonradiative Shockley-Read-Hall recombination. Finally, the study estimates the characteristics temperature of the mu LEDs using temperature-dependent EL measurement, revealing that blue mu LEDs exhibit a significantly large value of characteristic temperature approximate to 1926 K. The study investigates the size-dependent characteristics (chip diameter 100-10 mu m) of InGaN-based blue and green micro-light-emitting diodes (mu LEDs) concerning their electrical and optical properties. The study analyzes the size-dependent external quantum efficiency, optical power, and peak wavelength shift between blue and green mu LEDs and related phenomenon. The study also estimates the characteristics temperature of the mu LEDs using temperature-dependent electroluminescence measurement.image (c) 2024 WILEY-VCH GmbH