Athermal annealing of structure damage in GaAs

Abstract

The results are analysed of athermal annealing of structure defects, which are the nonradiative recombination centres in irradiated p‐GaAs. Annealing processes are studied by the recovery of electroluminescence quantum yield upon nonequilibrium charge‐carrier injection in the range of 77 to 300 K. The experimental data analysis makes it possible to suggest that upon charge‐carrier injection activation of migration takes place of B‐type defects with the level Ec – 0.03 eV, which are the sticking centres for electrons. In the course of migration these defects annihilate with nonradiative recombination centres annealed at 240°C.

Photoluminescence Analysis of Injection-Enhanced Annealing of Electron Irradiation-Induced Defects in GaAs Middle Cells for Triple-Junction Solar Cells

“…It is observed that the defect removal rate 𝜆 follows an exponential law, which is similar to the following 056102-2 form of the Arrhenius law [10] 𝜆 = 𝜆 0 exp(−𝐸 in,ex /𝑘 B 𝑇 ),…”

“…The fraction of unannealed defects versus the injection-enhanced annealing time follows a first-order kinetic. [10] Therefore, the radiation-induced defects are annihilated in accordance with…”

“…For a given level of the injection current density, the injection-enhanced annealing processes were investigated by the change of PL peak intensity. The fraction of unannealed defects 𝑓 was obtained from [9]…”

Volume 6: Experiment Facility Spectrum Tailoring (HFIR Futures – Enhanced Capabilities Series)

“…Athermal effects can cause defect recovery, strain relaxation, gas and defect diffusion, phase transformations, and gas resolution from bubbles. Such transient irradiation-induced processes are experimentally well documented in the literature for ceramics (Lang 1976, Lomako 1980, Lang 1982, Assmann 1978, Matzke 1983, Matzke 2000, Zinkle 2002) under neutron, fission, ion, electron and laser irradiations. These processes are often referred to as athermal because they are temperature independent or weakly dependent on temperature and cannot be described as thermally activated (activation energies below 0.2 eV).…”