Deep Double Donor Research Articles

Applicability of the deformation-potential approximation to deep donors in silicon.

Several deep double donors due to sulfur and selenium impurities, both isolated and in pairs, have been investigated in infrared-absorption and uniaxial-stress experiments. The study of several similar centers in their different charge states allows trends in parameters to be revealed. Particular attention is given to the applicability of effective-mass theory (EMT) and the deformation-potential approximation (DPA) to the various states studied. The np excited states are well described by EMT and hence their behavior under stress by the DPA. The deep 1s ground states do not follow DPA but shift linearly with respect to the center of gravity of the conduction bands with shift rates that increase with the ionization energy of the centers. Excited 1s states which are deeper than predicted by EMT are also observed to deviate from DPA. A perturbation approach beyond the DPA is developed to fit and compare data. For nontetrahedral centers the stress lifts their orientational degeneracy. The 1s(${A}_{1}^{+}$)\ensuremath{\rightarrow}ns transitions of chalcogen pairs are well described by DPA if matrix elements that couple the ns states are accounted for. For some centers, stress-induced crossings between allowed and forbidden states reveal information on states [1s(E) and spin-triplet states] that are not accessible by dipole transitions.

Characterization of an Anion Antisite Defect as a Deep Double Donor in InP

Characterization of an Anion Antisite Defect as a Deep Double Donor in InP

The influence of the RC product on capture cross section measurements in semiconductors

A detailed model is developed to study the influence of the sample RC product on capture cross section measurements and to enable the determination of absolute values of capture cross sections from such measurements. The model is tested on the deep double donor of selenium in silicon. It is shown that the value of the RC product should be at least a factor of ten smaller than the time constant of the capture cross section in order to avoid appreciable errors in the determination of capture cross sections. Such errors remain easily undetected in an ordinary analysis of capture cross section measurements.

ODMR studies of antisite-related luminescence in GaP

By the use of ODMR, we have detected and identified two different antisite defects which contribute to newly-reported infrared luminescence observed in GaP. The antisite proper, P Ga, gives rise to a spin- 1 2 resonance; the associated luminescence originates in the DA pair recombination of an electron trapped at the deep double donor P + Ga with a distant shallow acceptor. An impurity-associated centre of the form P Ga · Y P is observed in a spin-triplet state via a distinct luminescence band which originates in electron-hole recombination localised at the defect.