arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2008.02466cond-mat.mtrl-sciphysics.chem-ph
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单层和少层磁性半导体CrPS4的结构和光学性质

Structural and optical properties of single- and few-layer magnetic semiconductor CrPS4

Jinhwan Lee, Taeg Yeoung Ko, Jung Hwa Kim, Hunyoung Bark, Byunggil Kang, Soon-Gil Jung, Tuson Park, Zonghoon Lee, Sunmin Ryu, Changgu Lee

摘要:

原子薄的二元二维(2D)半导体根据其组成、结构和厚度表现出不同的物理性质。通过在这些材料中添加另一种元素,这将导致形成三元2D材料,其性质和结构将发生很大变化,并且可以探索显着扩展的应用。在这项工作中,我们报告的结构和光学性质的原子薄硫代磷酸铬(CrPS 4),三元反铁磁半导体。通过X射线衍射和电子衍射揭示了它的结构细节。透射电子显微镜显示,优先裂开的边缘是平行的对角线铬原子行,这很容易确定他们的晶体取向。强的平面内光学各向异性诱导的双折射,也使得能够使用偏振显微镜有效地确定晶体取向。拉曼光谱首次探测到晶格振动,并表现出显着依赖于剥离到单层的晶体的厚度。由反射率对比度确定的光学吸收主要由位于Cr 3+离子的d-d型跃迁主导,这也是1.31 eV处的主要光致发光峰的原因。在吸收和发射光谱的光谱特征表现出显着的厚度依赖性,并暗示了高的单层CrPS 4的光化学活性。目前的结构和光学研究为这种新型磁性半导体的进一步研究和应用奠定了坚实的基础。

英文摘要:

Atomically thin binary 2-dimensional (2D) semiconductors exhibit diverse physical properties depending on their composition, structure and thickness. By adding another element in those materials, which will lead to formation of ternary 2D materials, the property and structure would greatly change and significantly expanded applications could be explored. In this work, we report structural and optical properties of atomically thin chromium thiophosphate (CrPS4), a ternary antiferromagnetic semiconductor. Its structural details were revealed by X-ray and electron diffractions. Transmission electron microscopy showed that preferentially-cleaved edges are parallel to diagonal Cr atom rows, which readily identified their crystallographic orientations. Strong in-plane optical anisotropy induced birefringence that also enabled efficient determination of crystallographic orientation using polarized microscopy. The lattice vibrations were probed by Raman spectroscopy for the first time and exhibited significant dependence on thickness of crystals exfoliated down to single layer. Optical absorption determined by reflectance contrast was dominated by d-d type transitions localized at Cr3+ ions, which was also responsible for the major photoluminescence peak at 1.31 eV. The spectral features in the absorption and emission spectra exhibited noticeable thickness-dependence and hinted a high photochemical activity for single layer CrPS4. The current structural and optical investigation will provide a firm basis for future study and application of this novel magnetic semiconductor.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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