Optical Intensity Spectrum for GaN-Based Light Emitting Diodes

Recently, wurtzite-strained quantum wells have been studied intensively in order to realize RGB diode laser characteristics. For the theoretical analysis, the main goal in the relevant literature is maximizing optical gain peak in the desired wavelength. On the other hand lattice mismatch between substrate and barrier of the quantum well in the wurtzite-strained materials, causes large amount of defect density which is a linewidth broadening parameter in the optical gain or intensity spectrum.In our analysis, the first step consists of finding valence bands eigenvalues and light hole or heavy hole or crystal-field split-hole eigenvectors. The Luttinger-Kohn Hamiltonian is used to give the valence band structure of quantum well while strain effect and piezoelectric polarizations are considered. This approach is renowned as K.P method. The multiband effective-mass equations in the K.P approach may be solved by Finite difference method (FDM) or transfer matrix method (TMM) [1]. The InGaN/GaN and GaN/AlGaN quantum wells with various length and indices of alloying are examined; and spontaneous emission rate spectrum for a white GaN-based light emitting diode is obtained.