Frequency Shift with Temperature as Evidence for Donor-Acceptor Pair Recombination in Relatively Puren-Type GaAs

Abstract

Photoluminescence spectra of relatively pure GaAs display four emission bands at low temperatures, with energies near 1.51,1.49,1.455, and 1.42 eV. We report evidence that the 1.49-, 1.45-, and 1.42-eV bands are, respectively, a donor-acceptor recombination band, as suggested by Gershenzon, and two weaker replicas displaced by one and two phonons. With increasing temperature in the range from 25 to 35°K, the 1.49-eV band shifts slightly toward higher energy and is quenched in favor of the 1.51-eV band, while the total emission remains constant. The two lower energy bands change in frequency and intensity in exactly the same manner as the 1.49-eV band. We interpret the shift toward higher energy as due to an increasing importance of recombination of more closely spaced donor-acceptor pairs, and the quenching of the recombination band as due to increasing ionization of the donors. In addition, slight variations of the properties of the 1.49-eV band with increasing excitation intensity were noted which are compatible with the donor-acceptor recombination hypothesis.

High Purity GaAs Nanowires Free of Planar Defects: Growth and Characterization

“…This behavior is typical of DAP recombination. [41,42] Similar behavior is evident in the impurity emission peak of Figure 3. Further, time-resolved measurements are consistent with DAP recombination: [43] the peak red-shifts with time after the excitation pulse (Fig.…”

Characterization of CuIn(Ga)Se2 Thin Films

“…Indeed such values are typical for semiconductors, which are weakly compensated, e.g. 4 meV/3 decades in GaAs [13].…”

“…The LO-phonon structure of the recombinations I and II are typical for recombinations involving effective mass like donors and acceptors in direct band gap semiconductors [13].…”

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“…This conclusion has been obtained from the shift of peak energy as a function of light excitation intensity, sample temperature, and donor concentration [3]. All these influences change the average recombination distance, resulting in an energy change of the Coulomb term.…”