Features of Recombination Radiation of GaAs Type Semiconductors with the Participation of Fine Acceptor Levels in a Magnetic Field

Using the method of Picus and Beer invariants, general expressions are obtained for the total intensity I and the degree of circular polarization Рcirc.of the luminescence of GaAs-type semiconductors with the participation of shallow acceptor levels in a longitudinal magnetic field H. Special cases are analyzed depending on the value and direction of the magnetic field strength, as well as on the constants of the g-factor of the acceptor g1,g2and the conduction band electron ge. In the case of a strong magnetic field H// [100], [111], [110], a numerical calculation of the angular dependence of the quantities I and Рcirc.was performed for some critical values of g2/g1, at which Рcirc.exhibits a sharp anisotropy in the range from −100% to +100%, and the intensity of the crystal radiation along the magnetic field tends to a minimum value.

Inhibiting radiative recombination rate to enhance quantum yields in a quantum photocell

Inhibiting the radiative radiation is an efficient approach to enhance quantum yields in a solar sell.This work carries out the inhibition of radiative recombination rate(RRR)in a quantum photocell with two coupled donors.We perform explicit calculations of the transition rates,energy gaps and the absorbed solar wavelength-dependent RRR,and find that two different regimes play the crucial roles in inhibiting RRR.One is the quantum coherence generated from two different transition channels,the other includes the absorbed photon wavelength and gaps between the donor and acceptor in this proposed photocell model.The results imply that there may be some efficient ways to enhance the photoelectron conversion compared to the classic solar cell.

Total dose effects on the g–r noise of JFET transistors

Silicon junction field effect transistors（JFETs） have been exposed to Co-（60）-rays to study radiationinduced effects on their dc characteristics and noise. The devices have been irradiated and measured at room temperature up to an accumulated 100 krad（Si） dose of radiation at a dose rate of 0.1 rad（Si）/s. During irradiation,the generation–recombination（g–r） noise increase has been observed while the dc characteristics of the transistors were kept unchanged. The increasing of the density of the same type point defects and their probability of trapping and detrapping carriers caused by irradiation have been used to explain the g–r noise amplitude increase, while the g–r noise characteristic frequency has only a slight change.