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The frequencies and dampings of the zone-center optical phonons E2 and A1(LO) in wurtzite-type GaN and AlN layers have been measured by Raman spectroscopy in the temperature range from 85 to 760 K. The GaN layer was grown by metalorganic vapor phase epitaxy and the AlN layer by molecular beam epitaxy both on sapphire substrate. The experimentally obtained frequencies and dampings are modeled by a theory taking into account the thermal expansion of the lattice, a symmetric decay of the optical phonons into two and three phonons of lower energy, and the strain in the layers induced by the different thermal expansion coefficients of layer and substrate. The results were used to determine the local temperature of a GaN pn diode in dependence on the applied voltage.

A detailed analysis of the photoinduced current transients of differently grown CdTe:Cl samples was performed in the 100–140 K range in order to investigate the influence of different growth techniques (sublimation, Bridgman method, and traveling heater method) on compensation defects. While studying the experimental results the analysis of the transients turned out to be a crucial point. With the conventional two‐gate technique only one trap with misleading trap parameters could be identified in each sample. Analyzing the transients with the regularization method proposed recently [C. Eiche, D. Maier, M. Schneider, D. Sinerius, J. Weese, K. W. Benz, and J. Honerkamp, J. Phys. Condens. Matter 4, 6131 (1992)], three traps could be identified in each sample. Only one of these traps leads to an activation energy and a cross section approximately the same for the different samples. The other two traps of each sample depend on the growth technique.

Cd1−xZnxTe crystals grown by the traveling heater method have been investigated by low‐temperature photoluminescence. The excitonic energy gap as a function of the alloy composition was determined over the complete range of x=0 to x=1. The composition dependent broadening of the neutral acceptor bound exciton (A 0X) line was determined. Theoretical calculations, where the A 0X exciton is treated within the pseudodonor model and the conduction/valence band offset between CdTe and ZnTe is taken into account, give close agreement with the experiment for x≤0.77. Evidence for clustering of Zn atoms is found for x≥0.77.

It is shown that a recently proposed analysis of deep level transient spectroscopy signals with a regularization method by Batovski et al. [J. Appl. Phys. 74, 291 (1993)] can be simplified significantly by calculating the relaxation time spectrum of the capacitance transient with a regularization method directly.