A. O. Sofienko | Searcharxiv

arXiv2011

Specific features of the luminescence and conductivity of zinc selenide on exposure to X-ray and optical excitation

The set of experimental data on the X-ray-excited luminescence and X-ray induced conductivity of ZnSe are compared to the data on the photoluminescence and photoconductivity. It is experimentally established that the current-voltage characteristics and the kinetics of phosphorescence and current relaxation depend on the type of excitation. It is found that the external electric field influences the intensity and shape of bands in the luminescence spectra. It is shown that the character of excitation defines the kinetics of recombination, charge carrier trapping, and conductivity in wide-gap semiconductors.

cond-mat.mtrl-sci↗

arXiv2011

Kinetics of Charge Transport in Wide-Band Semiconductors at the Detection of X-Ray Radiation

As a result of absorption of X-ray quantum in a semiconductor, the generation of electron-hole pairs takes place in a small volume (diameter < 0.5 mkm). Their surplus energy is lost due to the scattering on phonons of the crystal lattice. Spatial distribution of the charge carriers makes the form of current pulse on electrodes of the crystal complicated when an external electric field is applied. We present a logical chart of construction of basic kinetic model of X-ray conductivity in semiconductors that uses the successive in time calculation of the spatial distribution of free charge arriers and the diffusive-drift model of motion of free carriers in a solid. The basic form of current pulse in an external circle was obtained in the analytical kind for the case of an ideal semiconductor, e.g. that does not contain deep traps and recombination centers, as well as for the case of a crystal with dominant shallow or deep traps of electrons and holes.

cond-mat.mtrl-sci↗