OPTICAL-PROPERTIES OF HIGH-QUALITY GA1-XINXAS1-YSBY INAS GROWN BY LIQUID-PHASE EPITAXY/

The photoluminescence (PL) of InAs and GaInAsSb/InAs epilayers grown b y Gd-doped liquid-phase epitaxy (LPE) has been investigated using a do uble-modulation Fourier transform infrared spectrometer (FTIR). The sp ectra were composed of peaks due to band-to-band, band-to-impurities, and exciton recombinations. The excitation power, temperature and Gd c oncentration dependences of these features were studied. The temperatu re dependence of the band-to-band transition energies was examined by measuring FTIR, transmission spectra and by comparing experimental res ults with those obtained with an empirical formula. A PL full width at half-maximum (FWHM) as narrow as 4.35 meV has been achieved for GaInA sSb epilayers grown from Gd-doped melt indicating high purity of epila yers. Raman scattering measurements of GaInAsSb epilayers showed a two -mode behavior for the optical phonons, indicating that homogeneous, h igh-quality epilayers were achieved.