Uniaxial stress influence on heavy and light hole spectrum, wave functions and polarization modes in p AlGaAs/GaAsP/n AlGaAs diode heterostructuresтезисы доклада
Дата последнего поиска статьи во внешних источниках: 29 мая 2015 г.
Место издания:Aristotle University of Thessaloniki Thessaloniki, Greece
Первая страница:180
Аннотация:The Luttinger-Kohn Hamiltonian with strained terms was self consistently solved with Poisson equation for the electrostatic potential using the finite-difference kp method and “Heterostructure Design Studio 2.1” program was used for numerical calculations of quantum size levels, wave functions and optical gain in p-AlGaAs/GaAsP/n-AlGaAs diode structures under compression up to 10 kbar in [110] direction at 77 K. “Heterostructure Design Studio 2.1” program permits to analyze the wave functions and find a degree of light hole and heavy hole “nature” of each level in quantum well (QW) at any pressure. After setting up the possible optical transitions in the level system, the program permits to calculate the values of electron-photon interaction matrix elements for these transitions and, according to the well known method, optical gain for TM and TE polarization modes. The results of optical gain calculations for the mentioned above structures permit to conclude that in QWs with “light hole up” hole energy spectrum uniaxial compression leads to significant increase of TE mode and minor decrease of TM mode. The evident advantage of TE mode is connected with upward shift of heavy hole levels and downward one of the LH1 level in the QW under compression, that increase the input of heavy hole states into optical transitions. According to the calculations, uniaxial stress may be used not only for wave length tuning but for modification of emitted light polarization as well. The performed calculations are in a good agreement with the previous experimental results on the electroluminescence under uniaxial stress. The electroluminescence spectra maximum blue shift is quantitatively described by the optical gap change under compression, and the observed electroluminescence intensity increase can be referred to TE mode enhancement.