Temperature Dependent Excitonic Transition Energy and Enhanced Electron-Phonon Coupling in Layered Ternary SnS2-xSex Semiconductors with Fully Tunable Stoichiometry

Molecules

Hung-Pin Hsu¹  Chi-Feng Tsai²  Der-Yuh Lin²  Cheng-Wen Wang²  Yu-Tai Shih³ 

[1] Department of Electronic Engineering, Ming Chi University of Technology, Taishan, New Taipei City 243, Taiwan;Department of Electronic Engineering, National Changhua University of Education, Changhua City 500, Taiwan;Department of Physics, National Changhua University of Education, Changhua City 500, Taiwan;

关键词: 2D semiconductors;    chemical–vapor transport;    van der Waals;   

DOI  :  10.3390/molecules26082184

来源: DOAJ

【 摘 要 】

In this study, a series of SnS_2-xSe_x (0 ≤ x ≤ 2) layered semiconductors were grown by the chemical–vapor transport method. The crystal structural and material phase of SnS_2-xSe_x layered van der Waals crystals was characterized by X-ray diffraction measurements and Raman spectroscopy. The temperature dependence of the spectral features in the vicinity of the direct band edge excitonic transitions of the layered SnS_2-xSe_x compounds was measured in the temperature range of 20–300 K using the piezoreflectance (PzR) technique. The near band-edge excitonic transition energies of SnS_2-xSe_x were determined from a detailed line-shape fit of the PzR spectra. The PzR characterization has shown that the excitonic transitions were continuously tunable with the ratio of S and Se. The parameters that describe the temperature variation of the energies of the excitonic transitions are evaluated and discussed.

【 授权许可】

Unknown