Adiabatic bond charge model for lattice dynamics of ternary chalcopyrite semiconductors

Abstract

The adiabatic bond charge model of Rustagi and Weber is extended to study lattice dynamical properties of ternary chalcopyrite semiconductors AgGaS 2 , AgGaSe 2 , CuInS 2 , CuInSe 2 , CuGaS 2 , CuGaSe 2 , CuAlS 2 and CuAlSe 2 . The new model calculations agree well with the results of Raman/IR and neutron measurements of Brillouin zone center phonon frequencies for both low and high frequency modes which was difficult for other phenomenological lattice dynamical models.

Exploration and Size Engineering from Natural Chalcopyrite to High-Performance Electrode Materials for Lithium-Ion Batteries

“…The Raman analysis of CFS-1/2/3 was conducted, and the Raman spectra are presented in Figure b; the stronger peaks were located at 280/271/287 cm –1 in CFS-1/2/3, corresponding to the A 1 mode, and the peak at 469 cm –1 in CFS-1/3 was related to the E mode. The peaks at 212 and 211 cm –1 in CFS-1/2 were ascribed to the B 1 mode, and a weak peak at 349 cm –1 in CFS-3 corresponded to the B 2 mode, which were in good agreement with previous reports. − It was obvious that the three samples had various vibrational modes, which may be concerned with particle sizes, but B 2 and E were polar Raman-active modes, showing transverse optical and longitudinal optical modes, which needed to be further investigated. The FT-IR analysis was applied to clarify the band, and the spectra are shown in Figure c.…”

“…The peaks at 212 and 211 cm −1 in CFS-1/2 were ascribed to the B 1 mode, and a weak peak at 349 cm −1 in CFS-3 corresponded to the B 2 mode, which were in good agreement with previous reports. 36−39 It was obvious that the three samples had various vibrational modes, which may be concerned with particle sizes, 35 but B 2 and E were polar Raman-active modes, showing transverse optical and longitudinal optical modes, 40 which needed to be further investigated. The FT-IR analysis was applied to clarify the band, and the spectra are shown in Figure 1c.…”

Temperature dependence of band gaps in semiconductors: Electron-phonon interaction

“…38 Semiempirical calculations based on the adiabatic bond charge model have also been published. 39 We display in Fig. 5 the phonon dispersion relations of CuGaX 2 (X = S, Se, Te) calculated by using the PBEsol approximation.…”

Raman Scattering Study of Mixed Quaternary AgxGaxGe1−xSe2 (0.167 ≤ x ≤ 0.333) Crystals

“…In terms of optical mode frequencies and symmetries our results are in very good agreement with those reported earlier in Refs. [9] and [10], but we benefited greatly from the analysis of vibrational patterns of selected modes, especially the only fully symmetric A 1 mode.…”

“…As already mentioned, apart from the crystallographic structure of mixed Ag x Ga x Ge 1− x Se 2 compounds, their nonlinear optical and photovoltaic properties, photoconductivity, and electronic band structure are well documented in the recent past . To the best of our knowledge, however, there are no reports on the transformation of phonon spectra of mixed Ag x Ga x Ge 1− x Se 2 crystals upon variation of composition x , despite of the fact that lattice dynamics properties of the end‐member compounds AgGaSe 2 and GeSe 2 were studied extensively both experimentally and theoretically. Probably, this is a consequence of a rather large unit cell of mixed crystals and, correspondingly, large number of expected phonon branches.…”