First-Principles Study on the Stabilities, Electronic and Optical Properties of GexSn1-xSe Alloys

Nanomaterials

Qi Qian¹  Lei Peng¹  Yucheng Huang¹  Liping Sun¹  Yu Cui¹  Jinyan Du¹ 

[1] College of Chemistry and Material Science, The Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, Anhui Normal University, Wuhu 241000, China;

关键词: GeSe monolayer;    SnSe monolayer;    alloy;    first-principles;    electronic property;    optical property;   

DOI  :  10.3390/nano8110876

来源: DOAJ

【 摘 要 】

We systematically study, by using first-principles calculations, stabilities, electronic properties, and optical properties of Ge_xSn_1-xSe alloy made of SnSe and GeSe monolayers with different Ge concentrations x = 0.0, 0.25, 0.5, 0.75, and 1.0. Our results show that the critical solubility temperature of the alloy is around 580 K. With the increase of Ge concentration, band gap of the alloy increases nonlinearly and ranges from 0.92 to 1.13 eV at the PBE level and 1.39 to 1.59 eV at the HSE06 level. When the Ge concentration x is more than 0.5, the alloy changes into a direct bandgap semiconductor; the band gap ranges from 1.06 to 1.13 eV at the PBE level and 1.50 to 1.59 eV at the HSE06 level, which falls within the range of the optimum band gap for solar cells. Further optical calculations verify that, through alloying, the optical properties can be improved by subtle controlling the compositions. Since Ge_xSn_1-xSe alloys with different compositions have been successfully fabricated in experiments, we hope these insights will contribute to the future application in optoelectronics.

【 授权许可】

Unknown