STRAIN AND CRYSTALLOGRAPHIC ORIENTATION EFFECTS ON INTERBAND OPTICAL MATRIX-ELEMENTS AND BAND-GAPS OF [11 ]-ORIENTED III-V EPILAYERS/

We report a derivation of the 4 X 4 Luttinger valence band and Bir-Pik us strain Hamiltonians valid for any [11l]-oriented epilayers. It is s hown that epitaxial layers grown on substrates oriented in certain of the [11l] directions exhibit anisotropic optical transition matrix ele ments. This anisotropy is predicted to have its maximum for the (110) surface. For pseudomorphic epitaxial layers, calculations indicate tha t the zone center band gap of these structures is changed due to the e ffects of strain, with the largest changes occurring for those structu res grown on the (111) surface. (C) 1995 American Institute of Physics .