Raman scattering in α-In2Se3 crystals

Structural and optical characterization of single-phase γ-In2Se3 films with room-temperature photoluminescence

“…There are four resolved phonon structures in each Raman spectrum, with one main mode located at 149.4 cm −1 . The two Raman modes located at 178.6 and 203.7 cm −1 have been observed in the reported Raman spectra of both ␥-In 2 Se 3 [16] or ␣-In 2 Se 3 [17,18]. On the other hand, the two Raman modes located at 149.4 and 227.6 cm −1 appears at the same wave numbers as in the reported Raman spectra of only the ␥-In 2 Se 3 [19,20].…”

Interlayer-glide-driven isosymmetric phase transition in compressed In2Se3

“…166) is better than with other symmetries, matching well with the results of Popovic et al 10 We notice that others assigned R3m symmetry to phase I. [17][18][19] To clarify this, we carried out Raman spectra measurements (Fig. 2(a)), which may help to discover the subtle difference between them.…”

“…15,16 Despite great efforts on structural and electrical properties of In 2 Se 3 for decades, its ambient-condition structure remains confusing and contradictory. 10,[17][18][19][20] One possible reason is that X-ray diffraction (XRD) measurements in powders seem to be insensitive to closed symmetries, such as the centrosymmetric R-3m and noncentrosymmetric R3m symmetries. Furthermore, pressure or strain is a much more powerful controlling factor than temperature for driving transformations toward structures with higher density and smaller volume, and hence tuning properties of materials.…”

Amorphous effect on the advancing of wide-range absorption and structural-phase transition in γ-In2Se3 polycrystalline layers

“…The 142 cm −1 peak is related to the vibration mode of A 1 (TO) of α-In 2 Se 3 crystal26, and the 174 cm −1 mode closely correlates with the In-Se vibrations in a α-In 2 Se 3 thin film17. The 202 cm −1 peak is the A 1 (LO) mode of α-In 2 Se 3 , which is stronger if the Raman measurement was done on the basal plane (k|| c -axis)26. The 236 cm −1 mode also possesses the A 1 symmetry and which usually presents a little bit higher intensity on the edge plane with the incident light of k⊥ c -axis operation.…”