Strain effects on excitonic transitions in GaN: Deformation potentials.

摘要: We present the results of experimental studies strain effects on excitonic transitions in GaN epitaxial layers sapphire and SiC substrates, with emphasis determination deformation potentials for wurtzite GaN. Photoluminescence reflectance spectroscopies were performed to measure energy positions exciton x-ray-diffraction measurements conducted examine lattice parameters grown different substrates. Residual induced by mismatch constants thermal expansion between substrates was found have a strong influence determining energies transitions. The overall generated is compressive tensile substrate. uniaxial hydrostatic derived from results. Our yield ${\mathbf{b}}_{1}$\ensuremath{\approxeq}-5.3 eV ${\mathbf{b}}_{2}$\ensuremath{\approxeq}2.7 eV, as well components ${\mathbf{a}}_{1}$\ensuremath{\approxeq}-6.5 ${\mathbf{a}}_{2}$\ensuremath{\approxeq}-11.8 eV. \textcopyright{} 1996 American Physical Society.