Infrared reflectivity and Raman scattering in GeS

Local structure of technologically modified g-GeS2: resonant Raman and absorption edge spectroscopy combined withab initiocalculations

“…Moreover, interpretation of the 256 cm À1 mode as a breathing-type vibration of distorted rocksalt GeS microphase has also been made [4]. The very weak band detected at $200 cm À1 is in accordance with our calculated Raman peaks at 211 and 212 cm À1 for the SGe 3 -S 6/3 cluster that in turn are in excellent accordance with the 212 cm À1 B 3g mode for c-GeS [32]. For small c-GeS clusters implanted into pores of zeolites (X-GeS) this peak is located near $200 cm À1 and is the dominant peak (figure 1, Ref.…”

“…However, the shoulder at $237 cm À1 can only be related to the formation of new structural units all having tri-coordinated S or Ge (SGe 3/3 , SGe 3 -S 6/3 , and GeS 3/3 ) as no other clusters have any peaks below 250 cm À1 . The band near 237 cm À1 is a breathing-like A g mode [32] in the polarized spectra of c-GeS forb bb b polarization. It is known that the basic building block of c-GeS is a pyramid where both S and Ge atoms are three-fold coordinated.…”

Band Gap Tuning of Cu2ZnGeSxSe4-x Absorbers for Thin-Film Solar Cells

“…Instead, a second CZGSSe-like mode at 241 cm −1 gained in intensity, which was present only as a small shoulder in the spectrum of the sample annealed without GeS. Its position is close to a mode reported for GeS [18]. However, since the absorber composition was slightly Ge-poor, it is more likely that it was one more sulfoselenide mode related to vibrations of both S and Se anions.…”

Structural development in Ge-rich Ge–S glasses

“…One of the vibrational frequencies of the ethane-like unit is located near 255 cm -1 ; 240 cm -1 according to Lucovsky et al [8] and 255 cm -1 according to Jackson et al [12]. In the spectra of c-GeS, there are two intensive peaks at 212 and 238 cm -1 , which are the modes of double layer structure [14]. The peak at 220 cm -1 is considered to originate from these peaks.…”