Table 2 Experimental ambient-pressure frequency (ω0), pressure coefficient (δ), and Grüineisen parameter (\(\overline{\gamma }\)) of the Raman active modes observed from the SDD-GaSe film and the GaSe bulk.
Mode parameter | \({\omega }_{0}\) (cm−1) | \(\delta = \frac{d\omega }{dP}\) (cm−1/GPa) | \(\overline{\gamma }= \frac{1}{{\omega }_{0}}\frac{d\omega }{dP}\) (× 10–3 GPa−1) | Pressure range | |||
|---|---|---|---|---|---|---|---|
Film | Bulk | Film | Bulk | Film | Bulk | ||
\({E}_{1g}^{1}\) | 59.9 | 58.8 | 0.41 ± 0.02 | 0.26 ± 0.02 | 6.8 ± 0.3 | 4.4 ± 0.4 | 0–28 GPa |
\({E}_{2g}^{2} (TO)\) | 206.4 | 212.4 | 2.51 ± 0.04 | 2.35 ± 0.07 | 12.2 ± 0.2 | 11.1 ± 0.3 | 0–16 GPa |
2.31 ± 0.03 | 2.04 ± 0.06 | 11.2 ± 0.2 | 9.6 ± 0.3 | 0–28 GPa | |||
\({E}_{1g}^{2}/{A}_{1} (LO)\) | 251.4 | 1.58 ± 0.03 | 6.3 ± 0.1 | 0–16 GPa | |||
\({A}_{1g}^{1}\) | 133.2 | 133.1 | 3.26 ± 0.18 | 4.96 ± 0.18 | 24.5 ± 1.4 | 37.3 ± 1.4 | 0–5 GPa |
2.33 ± 0.04 | 2.41 ± 0.09 | 17.5 ± 0.3 | 18.1 ± 0.7 | 0–28 GPa | |||
\({A}_{1g}^{2}\) | 308.3 | 308.1 | 2.78 ± 0.16 | 3.85 ± 0.17 | 9.0 ± 0.5 | 12.5 ± 0.5 | 0–5 GPa |
2.29 ± 0.03 | 2.42 ± 0.06 | 7.4 ± 0.1 | 7.9 ± 0.2 | 0–28 GPa | |||
\({A}_{1} (TO)\) | 235.1 | − 4.84 ± 0.19 | − 20.6 ± 0.8 | 0–5 GPa | |||
− 2.09 ± 0.14 | − 8.9 ± 0.6 | 0–28 GPa | |||||
