An IR, optical, and electron-spin-resonance study of as-deposited and annealed a-Ge1−xCx:H prepared by rf sputtering in Ar/H2/C3H8

Abstract

Some optical and electronspinresonance properties of germanium rich aGe1 − x C x :H prepared by radio frequency sputtering in Ar/H2/C3H8

Characterization and Properties of Ge1–x–Cx:H Compounds Obtained by X‐ray CVD of Germane/Ethyne Systems: Effect of the Irradiation Dose

“…The signals around 825 cm -1 and 856 cm -1 can be due to both GeH 2 and to GeH 3 bending modes and to GeCH n (n=1,2) wagging modes. [1,[40][41][42] It is noteworthy that, in agreement with the above attributions of stretching signals between 2800 cm -1 and 3000 cm -1 , no band is observed in the range 770-780 cm -1 which is generally attributed to wagging vibration of the CH 3 group bound to germanium. This confirms that our solids contain only mono and dihydrocarbon groups.…”

“…4e). The three bands obtained at about 2000 cm -1 , 2025 cm -1 , and 2058 cm -1 are certainly attributable to the stretching vibrations of Ge-H bonds in the GeH n (n = 1-3) groups, [7,15,25,[37][38][39][40] but individual attributions can only be attempted. On the basis of our results, [32] and literature data, [7,15,25,[37][38][39][40][41][42][45][46][47] the band around 2025 cm -1 can be attributed to GeCGeH 2 or GeC 2 GeH, the band at about 2000 cm -1 to GeH 2 vibrating in inner cavities, or GeC 2 -GeH, and the band around 2058 cm -1 to GeH 3 , C 2 GeH 2 , or C 3 GeH.…”

“…[21,37] In the wavenumber region between 500 cm -1 and 900 cm -1 , the interpretation of the spectra is complicated by the presence of several signals leading to broad overlapped bands due to the GeCH n (n=1,2) and GeH 2 bending modes, the Ge-C stretching, the CH 2 rocking, and Ge-H wagging modes. [1,7,21,37,40,42] The possible shift of vibrational modes due to changes in the environment must also be taken into account. There is no complete agreement on the single assignments: Vilcarromero et al [7] found two bands at 560 cm -1 and 620 cm -1 in the spectrum of a-GeC:H alloy, obtained with the rf co-sputtering technique, which were assigned to the Ge-H wagging mode and to the Ge-C stretching mode, respectively.…”

Characterisation and Properties of Amorphous Nonstoichiometric Ge1−xCx:H Compounds Obtained from X-Ray Radiolysis of Germane/Ethylene Mixtures

“…In this range many bands are present, and the interpretation is difficult due to the presence of broad bands (which are envelopes of modes) and by the overlapping of GeϪC stretching with GeϪH wagging modes or with GeϪCH n and GeH 2 bending modes. [21,22,25] Moreover, in this region the deformation modes of (CH m ) n C/Ge (m ϭ 1Ϫ3; n ϭ 1Ϫ3) groups are expected. [21,24] The signals at 1385 cm Ϫ1 and 1458 cm Ϫ1 are attributable to the symmetrical and asymmetrical deformation modes of the (CH 3 ) n C groups (n ϭ 1Ϫ3).…”

Annealing effects on the bonding structures, optical and mechanical properties for radio frequency reactive sputtered germanium carbide films

“…In particular, their refractive index can be widely varied, with composition within the range of 2-4, which makes Ge 1Àx C x films promising candidates for applications in the field of multilayer antireflection and protection coating of IR windows [1,2]. In addition, Ge 1Àx C x films may provide the apparent tunability of the band gap over a very wide range, which may be important for photovoltaic applications [3][4][5][6]. In some of these applications, Ge 1Àx C x films subject to localized heating caused by friction or power dissipation, or endure an elevated temperature.…”