Osiekowicz M, Staszczuk D, Olkowska-Pucko K, Kipczak Ł, Grzeszczyk M, Zinkiewicz M, Nogajewski K, Kudrynskyi Z R, Kovalyuk Z D, Patané A, Babiński A, Molas M R
Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warszawa, Poland.
School of Physics and Astronomy, The University of Nottingham, Nottingham, NG7 2RD, UK.
Sci Rep. 2021 Jan 13;11(1):924. doi: 10.1038/s41598-020-79411-x.
The temperature effect on the Raman scattering efficiency is investigated in [Formula: see text]-GaSe and [Formula: see text]-InSe crystals. We found that varying the temperature over a broad range from 5 to 350 K permits to achieve both the resonant conditions and the antiresonance behaviour in Raman scattering of the studied materials. The resonant conditions of Raman scattering are observed at about 270 K under the 1.96 eV excitation for GaSe due to the energy proximity of the optical band gap. In the case of InSe, the resonant Raman spectra are apparent at about 50 and 270 K under correspondingly the 2.41 eV and 2.54 eV excitations as a result of the energy proximity of the so-called B transition. Interestingly, the observed resonances for both materials are followed by an antiresonance behaviour noticeable at higher temperatures than the detected resonances. The significant variations of phonon-modes intensities can be explained in terms of electron-phonon coupling and quantum interference of contributions from different points of the Brillouin zone.
在β-GaSe和β-InSe晶体中研究了温度对拉曼散射效率的影响。我们发现，在5至350 K的宽温度范围内变化温度，可以实现所研究材料拉曼散射中的共振条件和反共振行为。由于光学带隙的能量接近，在1.96 eV激发下，GaSe在约270 K时观察到拉曼散射的共振条件。对于InSe，由于所谓B跃迁的能量接近，在2.41 eV和2.54 eV激发下，分别在约50 K和270 K时出现共振拉曼光谱。有趣的是，两种材料观察到的共振之后都有反共振行为，且在比检测到的共振更高的温度下明显。声子模式强度的显著变化可以用电子-声子耦合以及布里渊区不同点贡献的量子干涉来解释。
