Effects of GaN barrier thickness on built-in electric field and internal quantum efficiency of blue InGaN/GaN multiple quantum wells LED structures

Abstract

The built-in electric field in an InGaN quantum well and emission wavelength are numerically evaluated at various GaN barrier thicknesses in blue InGaN/GaN/Al2O3 LED structures. The effect of GaN barrier thickness on the internal quantum efficiency of these structures was studied experimentally by temperature- and excitation-power-dependent photoluminescence measurements. In LED structures with 3-nm-thick GaN barriers in the active region the internal quantum efficiency at high excitation levels higher than that in LED structures with thicker GaN barriers. The results of measurements indicate that in structures with 3-nm-thick GaN barriers, the Auger recombination rate is reduced.