Study on Optical Properties of Indium-Graded Semipolar InGaN/GaN Quantum Well
The electronic and optical properties of indium-graded semipolar quantum well (QW) structures with different indium variation schemes and well widths have been investigated by 6 × 6 k · p calculations. Both increasing the indium composition difference between the maximum and the minimum points in the well layer and moving the location of the maximum indium composition in the opposite direction of the built-in field existing in the well layer of indium constant semipolar QW can improve the overlap of electron and hole wave functions, as well as the intensity of spontaneous emission rate spectra for y'- polarization of the indium-graded semipolar QW. With the increasing well width, the overlaps of optimized indium-graded semipolar QWs decrease more slowly than those of the indium constant QW, and the optical polarization ratios py'x'of the semipolar QWs increase more slowly than those of the indium constant one.