Vacancy- and acceptor-H complexes in InP

Abstract

Abstract. It has been suggested that iron in InP is compensated by a donor, related to the 2316 cm −1 local vibrational mode and previously assigned to the fully hydrogenated indium vacancy, V In H 4 . Using AIMPRO, an ab initio local density functional cluster code, we find that V In H 4 acts as a single shallow donor. It has a triplet vibrational mode at around this value, consistent with this assignment. We also analyse the other hydrogenated vacancies V In H n , n = 1, 3, and determine their structure, vibrational modes, and charge states. Substitutional group II impurities also act as acceptors in InP, but can be passivated by hydrogen. We investigate the passivation of beryllium by hydrogen and find that the hydrogen sits at a bond-centred site and is bonded to its phosphorus neighbour. Its calculated vibrational modes are in good agreement with experiment.

Spectroscopy of Proton Implanted GaN

“…In as-grown [13][14][15] and H-implanted 16 InP there is a strong band at 2316 cm -1 that has been assigned to a P-H stretching mode of a V In -H 4 complex. 14,15,17 A lower frequency band at 2201 cm -1 has also been assigned to a P-H stretching mode of V In -H. 14,17,18 Additional weak lines have been seen between these frequencies. 14, 16 Ewels et al 17 have calculated the frequencies of the V In -H n complexes and have proposed that the partial dissociation of the V In -H 4 complex upon annealing leads to the formation of V In -H n centers with fewer H atoms, and thus lower frequencies, to explain the presence of several Hstretching bands.…”

“…14,15,17 A lower frequency band at 2201 cm -1 has also been assigned to a P-H stretching mode of V In -H. 14,17,18 Additional weak lines have been seen between these frequencies. 14, 16 Ewels et al 17 have calculated the frequencies of the V In -H n complexes and have proposed that the partial dissociation of the V In -H 4 complex upon annealing leads to the formation of V In -H n centers with fewer H atoms, and thus lower frequencies, to explain the presence of several Hstretching bands. Similarly, in our GaN studies, we suggest that the N-H stretching modes we observe belong to a family of V Ga -H n complexes.…”

“…In a previous study of H and D implanted InP, similar results were obtained and no line splittings were observed, 16 even though the line observed at 2316 cm -1 has been assigned to a V In -H 4 complex. 14,15,17 It was found later that in samples where H and D had been introduced during growth (which gives rise to much sharper lines), the 2316 cm -1 band was split into a triplet by the presence of both H and D, but with a line splitting of only ~ 0.5 cm -1 , too small to have been observed in the implanted samples. 15 The line widths in our proton implanted GaN samples arẽ 5 cm -1 which would also prevent the observation of such small line splittings.…”

Phosphorus–hydrogen complexes in LEC‐grown InP

“…If H and D are present in the samples and the V In H 4 complex can be formed, then a total of five different types of complexes should exist by replacing H by D: H 4 , H 3 D, H 2 D 2 , HD 3 , and D 4 . By ab initio local-density-functional pseudopotential calculations using an 131-atom InP cluster, the vibrational frequencies of these five types of complexes have been evaluated [9]. There is one infrared active hydrogen stretching mode for H 4 , two for H 3 D and H 2 D 2 , one for HD 3 , and the corresponding numbers for the deuterium stretching modes.…”

“…For complexes with more than one H atom, the mode pattern is more complicated. Calculations for the V In H 4 complex have shown [9] that in InP:H:D samples six lines in the region of the H-stretching modes and additionally six lines in the region of the D-stretching modes are expected. First experiments on InP:H:D [10] showed that around the 2315.6 cm -1 line three additional lines are detected, while two lines appear in the region of the corresponding deuterium modes.…”