Quantitative Analysis of Valley–Orbit Coupling in Germanium Doped with Group-V Donors

Semiconductors - The wave functions of electrons localized at P, As, and Sb shallow donors in Ge are calculated in the envelope function approximation taking into account valley–orbit...     

On the Intracenter Relaxation of Shallow Antimony Donors in Strained Germanium

Semiconductors - Long-wavelength acoustic phonon-assisted relaxation rates for the excited 1s(T), 2p0, 2s, 3p0, 2p±, 4p0, and 3p± states of antimony donors in a germanium crystal are...     

Optimization of technology of growing GaN heterostructures with using diffractometry analysis

The procedure of optimization of growing the layers of III-N nitrides by the MOCVD technique using X-ray-diffraction analysis is considered. It is established that the structural perfection of the layers estimated from the measurement of rocking curves correlates with radiation characteristics of structures of light-emitting diodes (LED).     

Chemical Shift and Exchange Interaction Energy of the 1s States of Magnesium Donors in Silicon. The Possibility of Stimulated Emission

Semiconductors - The results of experiments aimed at the observation of split 1s states in Mg-doped Si are reported. From the results, it is possible to determine the chemical shift and exchange...     

Relaxation of the Excited States of Arsenic in Strained Germanium

Semiconductors - The relaxation times of the lower p states of the arsenic donor in a germanium crystal strained along the [111] crystallographic direction are studied. Measurements are performed...     

Frequency Tuning of Terahertz Stimulated Emission under the Intracenter Optical Excitation of Uniaxially Stressed Si:Bi

Semiconductors - The results of experimental and theoretical investigations of terahertz-emission-spectrum tuning by means of uniaxial stress of a silicon crystal doped with shallow bismuth donors...     

On the Possibility of Ramsey Interference in Germanium Doped with Shallow Impurities

Semiconductors - The dynamics of the formation and decay of coherent states of shallow impurity centers in crystalline germanium resonantly excited by a pair of laser pulses, following one another...     

Terahertz absorption and emission upon the photoionization of acceptors in uniaxially stressed silicon

Experimental data on the spontaneous emission and absorption modulation in boron-doped silicon under CO₂ laser excitation depending on the uniaxial stress applied along the [001] and [011] crystallographic directions are presented. Room-temperature radiation is used as the probe radiation. Low stress (less than 0.5 kbar) is shown to reduce losses in the terahertz region by 20%. The main contribution to absorption modulation at zero and low stress is made by A⁺ centers. Intersubband free hole transitions additionally contribute to terahertz absorption at higher stress. These contributions can be minimized by compensation.     

Effect of uniaxial stress on intervalley phonon-assisted relaxation of excited shallow-donor states in silicon

Results of calculations of the rate of intervalley scattering for excited states 2p _±, 2p ₀, and 1s of the Group V donors (phosphorus, antimony, and arsenic) in silicon in the case of electron-phonon interaction are reported. Anisotropy of the effective mass and degeneracy of electron states (related to six valleys for the conduction band) are taken into account. The extent of the effect of the shift of the energy of the ground state due to the potential of the central cell on the process of relaxation for various donors has been determined. The main attention has been paid to the dependence of the relaxation rate on the compressive strain of silicon in the crystallographic direction [100]. It is established that such strain can appreciably increase the lifetimes of working states in a laser operating on intracenter transitions for donors in silicon and increase the quantum efficiency and gain of such active medium.