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We have investigated in-plane photovoltage (IPV) and photoluminescence (PL) in sequentially grown Ga[sub 0.8]In[sub 0.2]As/GaAs and Ga[sub 0.8]In[sub 0.2]N[sub 0.015]As[sub 0.985]/GaAs quantum wells. Temperature, excitation intensity, spectral and time dependent study of the IPV, arising from Fermi level fluctuations along the layers of the double quantum well structure, gives valuable information about the nonradiative centers and hence about the optical quality of the GaInNAs quantum well. It also provides information about the radiative transition energies in all the layers. In order to obtain either the trap activation energies and the detrapping rates of photogenerated carriers in the GaInNAs the IPV results are analyzed in terms of a theoretical model based on random doping fluctuations in nominally undoped multilayer structures. The PL results are analyzed in terms of the band anticrossing model to obtain the electron effective mass from the coupling parameter C[sub NM]. [ABSTRACT FROM AUTHOR]

Presents a study in which raman and photoluminescence spectroscopies are used to characterize crystalline quality and interfacial strain in heterostructures. Effect of biaxial stress on electronic and vibronic energies; Measurement of gallium arsenide grown on silicon by molecular-beam epitaxy; Enhancement of the sensitivity of the Raman probe.

We have investigated the temperature dependence of the band gap energy in GaInNAs, GaNAs and InGaAs quantum wells. In the structures containing nitrogen the well-known S-shaped characteristic was observed at low temperatures. We explain this anomalous temperature behaviour by strong carrier localization in potential fluctuations at low temperatures. In the nitrogen free samples, there was no S-shaped behaviour and the empirical Varshni dependence was followed. [Copyright &y& Elsevier]