N–H related defects in GaAsN grown through chemical beam epitaxy

Abstract

The local vibration modes of N–H related defects in GaAsN are studied using isotopes. When GaAsN is grown through chemical beam epitaxy (CBE) using triethylgallium/tris(dimethylamino)arsenic/monomethylhydrazine gas, there are several local vibration modes (LVMs) in Fourier transform infrared (FTIR) spectra. Signals with stretching mode peaks at 2952, 3098, and 3125 cm−1 are reported, along with new wagging and stretching mode peaks at 960 and 3011 cm−1, which exist only in crystals grown through CBE. When the film is grown using deuterated MMHy as a nitrogen source, new peaks at 2206, 2302, 2318, 2245, and 714 cm−1 appear. This suggests that D related defects are created because of the deuterated MMHy. The ratios of frequencies of these new peaks to those obtained from crystals grown using MMHy are nearly 1.34. This suggests that all defects in GaAsN grown through CBE, which appear as LVMs, are N–H related defects. Especially, those with LVMs at 960 and 3011 cm−1 are new N–H defects only found in GaAsN grown through CBE.

Effects of source gas molecules on N–H- and N–D-related defect formations in GaAsN grown by chemical beam epitaxy

“…When deuterated MMHy was used as the N source to grow GaAsN crystals, many N-D-related defects were generated in the grown film. 28) The peak at 940 cm −1 is the second-harmonic mode of N at the As site (N As ), and this defect is not related to the N-H structure. 29) Other peaks are attributed to LVMs of N-H-related defects, and the peaks at 960 cm −1 corresponds to the wagging mode and those at 2952 and 3098 cm −1 to the stretching modes.…”

“…29) Other peaks are attributed to LVMs of N-H-related defects, and the peaks at 960 cm −1 corresponds to the wagging mode and those at 2952 and 3098 cm −1 to the stretching modes. 28) This indicates that the N source MMHy plays an important role of supplying the H atoms in the N-H-related defects. However, the formation of these defects is strongly affected by both the growth methods and conditions, and the effects of arsenic (As) and gallium (Ga) source gases on the defect formation are yet unclear.…”

Identification of N–H related acceptor defects in GaAsN grown by chemical beam epitaxy using hydrogen isotopes

“…H atoms are strongly bound to N and different types of N-H complexes are generated [14,15]. Theoretical calculations suggest that one of the N−H defects plays the role of a double acceptor [16].…”

Double acceptor in p-type GaAsN grown by chemical beam epitaxy

“…One reason for the degradation is attributed to the high concentration of residual acceptors in unintentionally doped ptype films, which limits the depletion region width of the solar cell and decreases the photogenerated current [11][12][13]. N-H related complexes are the major defects in InGaAsN grown by chemical beam epitaxy (CBE), metal organic chemical vapor deposition (MOCVD), and molecular beam epitaxy (MBE) with H-irradiation [14][15][16][17][18]. Theoretical calculations suggested that one of the N-H defects plays the role of a double acceptor [19].…”