Photoluminescence spectra as a function of temperature and laser excitation intensity of Si-doped Al0.3Ga0.7As grown by molecular beam epitaxy have been investigated for Si concentrations just lower and larger than the Mott critical value. A detailed lineshape analysis of the photoluminescence spectra in the lower doped samples reveals the increasing role of homogeneous broadening mechanisms, with respect to inhomogeneous ones, as the temperature raises. The fundamental gap shrinkage and the broadening of the photoluminescence line with increasing temperature are discussed in terms of phenomenological models. This allows to estimate some material dependent parameters related to electron-phonon interaction. In the largest doped samples, a structure appears in the photoluminescence spectra, due to the raising of the Fermi level in the conduction band.
Photoluminescence Analysis of Si doped AlxGa1-xAs near the Mott Transition Doping Density
CAPOZZI, VITO GIACOMO;PERNA, GIUSEPPE;
2004-01-01
Abstract
Photoluminescence spectra as a function of temperature and laser excitation intensity of Si-doped Al0.3Ga0.7As grown by molecular beam epitaxy have been investigated for Si concentrations just lower and larger than the Mott critical value. A detailed lineshape analysis of the photoluminescence spectra in the lower doped samples reveals the increasing role of homogeneous broadening mechanisms, with respect to inhomogeneous ones, as the temperature raises. The fundamental gap shrinkage and the broadening of the photoluminescence line with increasing temperature are discussed in terms of phenomenological models. This allows to estimate some material dependent parameters related to electron-phonon interaction. In the largest doped samples, a structure appears in the photoluminescence spectra, due to the raising of the Fermi level in the conduction band.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
