Effect of buffer layer thickness on recombination in zincblende InGaN/GaN quantum wells

Abstract InGaN/GaN quantum wells grown in the zincblende phase along the [001] direction are free of the internal electric fields that reduce the radiative recombination rate in conventional quantum wells grown along the c -axis in the wurtzite phase. However, heteroepitaxial growth and reduced thermodynamic stability compared to the wurtzite phase typically results in a significant density of stacking faults (SFs) in zincblende GaN, which impacts emission efficiency when they intersect quantum wells. Here it is shown that increasing the buffer layer thickness that lies between the substrate and the active region significantly reduces the density of SFs reaching the quantum well, and thereby increases the emission efficiency.