Answers are grounded in this paper and cite their sources.
We have measured the strength of the first-derivative peak observed below the band gap in photoreflectance spectra of semi-insulating GaAs and found that it is correlated with the bulk residual acceptor concentration. The apparent energy separation of the impurity peak is not fixed, but varies from sample to sample.
No takes yet. Share an insight, caveat, or question.
Brierley et al. (1990) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: