Acceptors in wide-gap semimagnetic semiconductors

Relaxation of highly excited carriers in wide-gap semiconductors.

The electron energy relaxation in semiconductors and insulators after high-level external excitation is analysed by a semi-classical approach based on a kinetic equation of the Boltzmann type. We show that the non-equilibrium distributions of electrons and holes have a customary Fermi-like shape with some effective temperature but also possess a high-energy non-Fermian 'tail'. The latter may ex...

Absorption spectra of wide-gap semiconductors in their transparency region

The linear absorption spectra of GaP, TiO2, ZnSe, and ZnS are measured in their transparency range using a twocolor, excite-probe Z-scan. ZnS has the lowest absorption coefficient ( 10 5 cm ) in the wavelength range 840–900 nm, making it an excellent material for use as a luminescence extracting lens in semiconductor laser cooling experiments. Direct observation of two-photon absorption in ZnSe...

Defects, Impurities and Doping Levels in Wide-Band-Gap Semiconductors

A fundamental understanding of the mechanisms governing the behavior of defects and impurities is essential to control doping in semiconductors. Wide-band-gap semiconductors, in particular, often exhibit doping-related problems. We discuss how rst-principles theoretical techniques can be applied to the calculation of formation energies and concentrations of native defects and dopant impurities....

Workshop on Defects in Wide Band Gap Semiconductors

Intrinsic limitations to the doping of wide-gap semiconductors

Doping limits in semiconductors are discussed in terms of the amphoteric defect model (ADM). It is shown that the maximum free electron or hole concentration that can be achieved by doping is an intrinsic property of a given semiconductor and is fully determined by the location of the semiconductor band edges with respect to a common energy reference, the Fermi level stabilization energy. The A...