CRYSTAL ORIENTATION EFFECT ON VALENCE-SUBBAND STRUCTURES IN WURTZITE-GAN STRAINED QUANTUM-WELLS

We analyze theoretically for the first time valence-subband structures in wurtzite-GaN strained quantum wells (QWs) for various crystal orie ntations. The calculation is based on the Bir-Pikus effective-mass the ory, where deformation potentials are determined by a semi-empirical t ight-binding method. The obtained results show that the hole effective masses of strained QWs with non-(0001) orientation, in particular, ar ound the (10 (1) over bar 2) orientation, are markedly lighter than th ose of (0001) cases. We also found that the optical matrix elements of non-(0001) strained QWs are twice as large as those for (0001) strain ed QWs.