Investigation of temperature dependent efficiency droop for light-emitting diodes on patterned-sapphire substrates with various depths
Date Issued
2016
Date
2016
Author(s)
Ju, Tze-Hung
Abstract
GaN-based Light-Emitting Diodes (LEDs) are typically grown on c-plane sapphire, or even patterned sapphire substrates (PSSs). In the same Epitaxy conduction, we designed three different depth Patterned Sapphire Substrates (2.55um, 2.65um, 2.75um). All of them are period of 3um and hexagonal arranged. We use Electroluminescence Measurement System with temperature controller to measure them from 5 ° C to 80 ° C and discuss their T-droop (The efficiency droop caused by increasing temperature) , and temperature tolerant. Moreover, we use the 266nm laser to do the Photoluminescence Measurement. After that, the sequence of the Epitaxy quality of them has been found. Consistent with the result measured by Electroluminescence Measurement System. It proves that LED with a better Epitaxy quality has a high temperature-tolerant.
Subjects
GaN-based Light-emitting diodes
Nano-Pattered Sapphire Substrates
Micro nanostructures
Electron-beam Lithography
Efficiency Droop
Type
thesis