Low temperature photoluminescence of lightly Si-doped and undoped MBE GaAs

Surface State Behavior and Neutralization of Impurities in Sulfur-Treated, Hydrogenated, and Annealed GaAs

“…Another peak near 1.8 eV appeared in the PR spectra only for the sulfur treated GaAs, and this peak is attributed to the transitions between the spin±orbit split-off band (E 0 + D 0 ) and the conduction band [38]. The variation of the PR intensity for this signal can be explained by a similar behavior as for E 0 .…”

“…The small shoulder in high energy of the (D 0 , X) line 1.5171 eV is considered to be from free excitons (X). The peak of the defectbound exciton (d, X) in the range between 1.504 and 1.511 eV and the peak at 1.493 eV related to carbon acceptors (e, A 0 ) c appear [36]. The peak at 1.5148 eV might be related to excitons bound to antisite defect complexes [36].…”

“…When the doping concentration becomes large, the surface electric field (F) increases according to Schottky's equation. The intensity of the PR signal (DR/R) is proportional to the variation of the F (DF) due to the modulation from the laser light [36]. Glosser and Bottka reported that the DF of the sample induced by an alternating band bending modulation (DV) was proportional to DV/F [37].…”

“…The PL spectrum of the as-grown GaAs shows several peaks. The peaks at 1.5137 and 1.512 eV are attributed to excitons bound to neutral donors (D 0 , X) and excitons bound to neutral acceptors (A 0 , X), respectively [36]. The small shoulder in high energy of the (D 0 , X) line 1.5171 eV is considered to be from free excitons (X).…”

Photoluminescence study of Al doping in GaAs grown by molecular-beam epitaxy

“…The lower-energy transition ͑peak C͒ involves a deeper defect ascribed to some complex of carbon by Briones and Collins. 18 The (e,A 0 ) and (D 0 ,A 0 ) structure of this luminescence feature was established by Skromme et al 8 Later, Chand et al 17 suggested the involvement of both C and Si in this complex, since they could only observe this luminescence line in their Si-doped MBE GaAs samples. The differential thermal ionization of the shallower carbon acceptor causes a more rapid quenching of the B peak relative to the defect-complex peak C with increase in temperature, as observed in our spectra ͑Fig.…”