Dresden 2014 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 53: Nitrides: Preparation of nonpolar and semipolar orientations

HL 53.1: Talk

Tuesday, April 1, 2014, 14:00–14:15, POT 151

Analytic solutions of kp-Hamiltonian for III-nitride semicondutors with arbitrary strain situation — •Michael Winkler, Rüdiger Goldhahn, and Martin Feneberg — Otto-von-Guericke-Universität, Magdeburg, Germany

Calculation of transition energies and optical polarization degrees in semi- and nonpolar wurtzite semiconductors demand new analysis schemes within kp-theory. We demonstrate that the Bir-Pikus Hamiltonian for nonpolar or semipolar material with arbitrary strain situation, following Hooke’s law, is analytically solvable for eigenenergies and eigenvectors. These results contribute to an in-depth understanding of valence band distances and relative oscillator strengths. We discuss valence band crossing and anticrossing behavior under symmetry not preserving strain at the Γ-Point.

The fully analytical parametrization of eigenvalues for semipolar wurtzite layers allows finally for a quick qualitative analysis of oscillator strengths and band order. The methodology allows for an easy expansion to pressure-dependent optical experiments. Calculational results are put in relation to experimental data. We find that valence band crossings are exotic events occuring under special conditions only, which is discussed in detail.