STRAIN EFFECTS ON THE BAND STRUCTURES OF GAN

The strain effects on the band structure of zincblende GaN are studied by using the ab initio linear muffin-tin orbital (LMTO) method. The v ariations of energy splitting with the strain component are calculated for some of the important eigenvalues. The strain effects on the band shape and band gap are discussed. It is found that the compressive (e xpansive) strain parallel to the (100) surface gives a narrower (wider ) X(1)(c)-Gamma(15)(v) band gap and a wider (narrower) Gamma(1)(c)-Gam ma(15)(v) band gap compared with that of the perfect zincblende GaN cr ystal. The band width along the Delta direction increases when the lat tice parallel to the (100) surface a(parallel to) is compressed and de creases when a(parallel to) is expanded. However, the band width along the Lambda direction decreases for both compressive and expansive str ain parallel to the (100) surface.