Springer Online Journal Archives 1860-2000
Electrical Engineering, Measurement and Control Technology
Abstract The influence of low-temperature annealing on the photoluminescence of GaAs/AlGaAs single-quantum-well structures treated in a low-energy CF4 plasma is investigated. It is established that annealing at 160–300 °C causes a decrease of the photoluminescence intensity of the quantum wells located in the near-surface region, while annealing at 350–450 °C leads to partial restoration of their photoluminescence. The activation energy for the diffusion of plasma-produced point defects and the activation energy for the annealing of these defects are determined. These energies are equal to 150 and 540 meV, respectively. It is discovered that the photoluminescence of the quantum wells near the substrate, which had a low intensity in the as-grown sample, increases after treatment in the plasma and decreases after subsequent annealing monotonically with increasing annealing temperature. Repeated treatment in a CF4 plasma leads to a repeated increase in the photoluminescence intensity of these quantum wells. It is theorized that the defects induced by the CF4 plasma form complexes with defects introduced during growth and that these complexes are not recombination centers. After low-temperature annealing, the complexes dissociate, and the nonradiative recombination centers are recreated.
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