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The effect of Nb doping of oxide perovskite SrTiO3 on the electronic properties is studied by semirelativistic linear muffin-tin orbital method with atomic sphere approximation (LMTO-ASA). The computational lattice constants are in good agreement with experimental data. The Fermi level of SrTi1−xNbxO3 with x⩾0.125 moves into the bottom of conduction band and the system shows metallic behavior. Due to the appearance of the charge impurity potential from Nb doping, there is a large distortion on the top of valence band for SrTi1−xNbxO3 with 0.125⩽x⩽0.25. The distortion becomes weak with x=0.5 because of the carriers screening effect. Our computational results also show that the Nb doping effect on the electronic structure of SrTi1−xNbxO3 cannot be described within a simple rigid-band model well. [Copyright &y& Elsevier]

Abstract: Using first-principles method we studied the compensation mechanism of As donor in Hg1− x Cd x Te based on the model Berding et al. (1998, 1999) of pair. We show that the binding of AsHg and results from donor-acceptor coupling, and the compensation of As donor can be clearly explained in terms of electronic deactivation by . The pairing physics derived from this study confirm the available theoretical and experimental results. [ABSTRACT FROM AUTHOR]

Abstract: Signatures associated with electronic states confined in two strained In x Ga1–x As/GaAs single quantum wells have been observed in its piezomodulated (PzR) and photomodulated (PR) reflectivity spectra. One comparison of the relative intensity between 11H and 11L signatures in PzR of GaAs/In0.14Ga0.86As SQW emphasizes the contribution of strain dependence of energies of the confined states; the other comparison of corresponding confined states between PzR and PR spectra in both samples has been introduced to interpret the discrepancy of the relative intensity in term of modulated strength, and the calculated ratio of energy shifts induced by strain to that of produced by surface electric field agree with the experimental observation. [Copyright &y& Elsevier]