Local-Vibrational-Mode Absorption of Two O-H Centres in GaP

Abstract

In LEC-grown GaP, two vibrational lines at 3250.9 cm ± ±1 and 3106.0 cm ± ±1 are measured and assigned to the stretching modes of two different O±H centres. In GaP containing both hydrogen and deuterium, two additional lines appear, both shifted to lower energies by the same factor r 1X346. This result shows that both O±H centres contain only one hydrogen atom. The O±D line at 2415 cm ± ±1 is split into two lines. This splitting possibly indicates a further example for resonant interaction of local modes with extended ones. The comparison with GaAs suggests the assignment of two lines to the analogous O±H centres in GaAs.

Vibrational Absorption of Hydrogen Bonded to Interstitial Oxygen in GaAs and GaP

“…Also in GaAs, two lines are known located at nearly the same frequencies (3108.0 and 3235.0 cm --1 ) [3]. As their properties are quite similar to those in GaP mentioned above, it was suggested [5] that they are possibly due to the same kind of centres as in GaP. In this paper, we investigate these two (O-H) centres in GaAs and GaP.…”

“…GaAs containing both H and D exhibits only one additional D-related line at 2455.0 cm --1 proving that this centre, called (O-H) A , consists of a single hydrogen atom bonded to oxygen [4], probably to off-centre O As as proposed by Pajot and Song [3]. In LEC-grown GaP, two vibrational lines at 3106.0 and 3250.9 cm --1 have been found and assigned to the stretching modes of two different (O-H) centres, because the corresponding lines could also be detected in the region of the D-vibrations [5]. However, the interpretation of the splitting of one of the deuterium counterparts remained questionable.…”

“…) The labellings (O-H) I and (O-H) II are interchanged here compared with those used in[5] 3. ) The half widths G inTables 1 and 2are the smallest measured ones.…”

“…As the intensity ratio of the three lines is the same in GaAs and GaP, the centre must have the same microscopic structure in both materials. Therefore, the suggestion for the occurrence of two D-lines in GaP proposed in [5] cannot be correct. This suggestion assumed that the centre contains only one H-atom and that the splitting of the D-line is due to the resonant interaction with an unidentified extended mode, in analogy to the results for H and D in AlSb:Se [17].…”

Vibrational Absorption of a Nitrogen–Oxygen Complex in GaP

“…However, S can be excluded, as GaP crystals doped with S ([S P ] % (0.5-2) Â 10 17 cm --3 ) do not show results different from those unintentionally doped with S. Also hydrogen can be excluded as a constituent, because the frequencies of the known H-centres in GaP (P-H [11], C-H [12], N-H [13], O-H [14]) are much higher (2000 to 3500 cm --1 ), and the experiments on a GaP crystal doped with deuterium revealed no difference in the spectra. However, S can be excluded, as GaP crystals doped with S ([S P ] % (0.5-2) Â 10 17 cm --3 ) do not show results different from those unintentionally doped with S. Also hydrogen can be excluded as a constituent, because the frequencies of the known H-centres in GaP (P-H [11], C-H [12], N-H [13], O-H [14]) are much higher (2000 to 3500 cm --1 ), and the experiments on a GaP crystal doped with deuterium revealed no difference in the spectra.…”