Localized Donor States Research Articles

Highly localized donor states in InSb and their pressure dependence

AbstractSome experimental results are given of the pressure dependence of Hall and Shubnikov‐de Haas effects in InSb doped with S and Se. For T = 4.2, 300, and 519 K a decrease of the free‐carrier concentration is observed due to the filling of the resonant impurity states lying highly in the conduction band. Interpreting the data with the simple Koster‐Slater model good agreement of the theory with experiment is obtained. More accurate conclusions could be drawn from such fits if the density of states in the conduction band and its dependence on pressure and temperature were better known.

Thermoelectric power in phosphorous doped amorphous silicon

Abstract Thermoelectric power and conductivity measurements have been made as a function of temperature on a series of a-Si specimens doped substitutionally with phosphorous. The samples were prepared by the glow discharge decomposition of silane containing predetermined concentrations of phosphine. The thermoelectric power of all the samples investigated was negative as expected. For the lightly doped specimens the thermoelectric and conductivity results support the model developed from previous work. Electron transport is in the extended states, but below room temperature there is an increasing contribution from tail state hopping. At higher doping concentrations the data can be interpreted in terms of transport through the extended states and the localized donor states, as suggested by the analysis of recent Hall effect results. The value of the intercept S 0 on the S axis at 1/T = 0 depends strongly on the position of the Fermi energy ∊F with respect to the mobility edge at ∊c. The movement of ∊F with...

Spin-flip Raman scattering from electrons in localized donor states in n-InSb

We report the first observation of spin-flip Raman scattering from electrons localized in shallow donor states in InSb. For a non-degenerate n-InSb sample (8×10 13 cm -3) measurements of the spin-flip Raman gain and the effective g-value as a function of the magnetic field show lineshapes and magnetic field dependences completely different to that of an InSb sample with the electron gas being in a degenerate regime (1.35×10 15 cm -3). For the 8×10 13 cm -3 InSb sample, at magnetic fields greater than 11.5 kG, a splitting of the spin-flip Raman line into two lines is observed which may be an indication that two shallow donor states with different effective g-values are concerned.

Electroluminescence in Amphoteric Silicon-Doped GaAs Diodes. II. Transient Response

An electrical and optical study has been made of the transient response of amphoteric Si-doped GaAs diodes. The luminescent turn-on and turn-off times were found to increase both with decreasing photon energy and with decreasing current drive. These results are consistent with a theory based on the wavy band model in which the recombination is from deep localized donor states and deep localized acceptor states.

The specific heat of vacuum reduced rutile (TiO 2) below 4.5°K

The extra specific heat of vacuum reduced rutile is reproduced by a model in which localized donor states feed a narrow impurity band.