中国物理B ›› 2026, Vol. 35 ›› Issue (5): 57801-057801.doi: 10.1088/1674-1056/ae40d9
Zhipeng Yan(闫志鹏)1,2,†, Xiaodong Yao(姚晓东)3, Guangyang Dai(代光阳)2,4, Chenkai Li(李辰恺)3, Qunfei Zheng(郑群飞)3, Jun Han(韩军)3, Ying Liu(刘影)3, and Xiaowei Sun(孙小伟)1,‡
Zhipeng Yan(闫志鹏)1,2,†, Xiaodong Yao(姚晓东)3, Guangyang Dai(代光阳)2,4, Chenkai Li(李辰恺)3, Qunfei Zheng(郑群飞)3, Jun Han(韩军)3, Ying Liu(刘影)3, and Xiaowei Sun(孙小伟)1,‡
摘要: The two-dimensional van der Waals ferromagnetic semiconductor CrI$_{3}$ provides an ideal platform for exploring the interplay among structural, electronic and magnetic degrees of freedom. In this work, we systematically investigate the thickness-dependent optical properties of five-layer and ten-layer CrI$_{3}$ under hydrostatic pressure up to 27.9 GPa by in situ Raman and UV-visible absorption spectroscopy. All A$_{\rm g}$ Raman modes exhibit a continuous blueshift with increasing pressure. The low-frequency modes ($\mathrm{A}_{\mathrm{g}}^{{1}}$-$\mathrm{A}_{\mathrm{g}}^{{3}}$) are mainly associated with enhanced interlayer coupling, whereas the high-frequency modes ($\mathrm{A}_{\mathrm{g}}^{{4}}$-$\mathrm{A}_{\mathrm{g}}^{{6}}$) reflect the suppression of surface vibrations. The Raman modes disappear at approximately 4.9 GPa for the five-layer sample and 11.2 GPa for the ten-layer sample, indicating a stronger strain sensitivity in thinner CrI$_{3}$. Optical absorption measurements show a pronounced redshift of the absorption edge, accompanied by bandgap narrowing from 2.26 eV to 1.26 eV in five-layer CrI$_{3}$. At comparable pressures, the five-layer sample consistently exhibits a wider bandgap than the ten-layer one, which is attributed to quantum confinement effects and reduced interlayer hybridization. Above 12.7 GPa, the bandgap reduction becomes less pronounced, probably due to enhanced Cr 3d/I 5p orbital overlap and strengthened superexchange interactions. These results reveal a clear layer-dependent structure-electronic coupling in CrI$_{3}$ under compression and provide useful insights into pressure modulation of van der Waals magnetic semiconductors.
中图分类号: (Infrared and Raman spectra)