A dual-blue light-emitting diode based on strain-compensated InGaN—AlGaN/GaN quantum wells

A strain-compensated InGaN quantum well (QW) active region employing a tensile AlGaN barrier is analyzed. Its spectral stability and efficiency droop for a dual-blue light-emitting diode (LED) are improved compared with those of the conventional InGaN/GaN QW dual-blue LEDs based on a stacking structure of two In0.18Ga0.82N/GaN QWs and two In0.12Ga0.88N/GaN QWs on the same sapphire substrate. It is found that the optimal performance is achieved when the Al composition of the strain-compensated AlGaN layer is 0.12 in blue QW and 0.21 in blue-violet QW. The improvement performance can be attributed to the strain-compensated InGaN—AlGaN/GaN QW, which can provide a better carrier confinement and effectively reduce leakage current. (condensed matter: structural, mechanical, and thermal properties)