Vibrational modes of a hydrogen-impurity centre in LEC-GaAs

The nitrogen–hydrogen–vacancy complex in GaAs

“…Therefore, we strongly suggest that in the Z -H complex, investigated in detail in Ref. [3], one hydrogen is bonded to nitrogen in the N As -V Ga defect. In Fig.…”

“…This means that there is a considerably enhanced forma- Fig. 2 Absorption spectra of the wagging (left) and stretching mode (right) of hydrogen bonded to nitrogen in the N-H-V Ga (Z-H in [3]) complex. The measurements were carried out on the same sample as used for Fig.…”

“…In Ref. [3], it was shown that the intensities of the Z-H LVMs decrease under sub-band gap illumination and simultaneously a new set of LVMs appears at slightly shifted frequencies. The investigation of this photoinduced effect led to the conclusion that the complex can be optically recharged at low temperatures and has an acceptor level (Z-H)/(Z-H) + in the region above the valence band edge between E v and E v + 0.5 eV.…”

“…These LVM lines are measured at T ≈ 7 K in the frequency region from 2900 to 3400 cm -1 and are assigned to stretching modes of hydrogen bonded to light residual impurity atoms as infered from the frequency ratio r = ω H /ω D of the hydrogen and related deuterium modes. The line at 2947.4 cm -1 is due to the N As -H stretching mode [1,2], while the line at 3000.0 cm -1 originates from an O-H stretching mode in a complex with one H [1,3]. Furthermore, lines at 3015.5, 3092.8, 3108.0, and 3235.0 cm -1 have been assigned to O-H modes in complexes containing one or two hydrogen atoms [4,5].…”

“…In Ref. [3], the H stretching mode at 3079.2 cm -1 with its associated wagging mode at 983.3 cm -1 were investigated, and the complex was labelled Z -H. The corresponding deuterium modes were also detected and proved that only one H is bonded to Z. However, it was not possible to distinguish, whether the origin of Z was oxygen or nitrogen.…”