Pham Trung D, Hien Tong D
Yersin University, 27 Ton That Tung, Ward 8, Dalat City, Lam Dong Province, Vietnam.
Faculty of Engineering, Vietnamese-German University, Binh Duong, Vietnam.
Phys Chem Chem Phys. 2023 Sep 20;25(36):24459-24467. doi: 10.1039/d3cp02978f.
The buckling hexagonal structure of GeTeP was studied by first-principles calculations. The newly proposed structure was proven to be stable by analyzing its cohesive energy, phonon dispersion, elastic constants and AIMD results. Poisson's ratio of the GeTeP monolayer is in the range 0.16-0.18, and Young's modulus is in the range 40.16-43.74 N m. The substituted Te atoms enhance the sp orbitals which strengthen the σ-bonds and therefore the thickness of the GeTeP monolayer is smaller than that of monolayer GeP. The GeTeP monolayer has an indirect band gap of 1.85 eV, which can be narrowed by strains. The compressive band gaps from -2% to -4% change the electronic structure from the indirect band gap into the direct band gap. Strains can also increase the light absorption rate () in the visible region, which is 2-3 × 10 cm at equilibrium. The GeTeP monolayer has a suitable band gap and an appropriate VBM and CBM position for hydrogen generation. Under strain rate of 4% and higher, the VBM and CBM remain at suitable positions for hydrogen production. Another advantage of the GeTeP monolayer is that its charge carrier mobilities are really high. The highest electron mobility is 1301.47 cm V s, and the highest hole mobility is 28627.24 cm V s, which are much higher than the mobility in monolayer GeP. The GeTeP monolayer has advantages for photocatalytic applications and it is necessary to perform further study on the material.
通过第一性原理计算研究了GeTeP的屈曲六边形结构。通过分析其结合能、声子色散、弹性常数和AIMD结果，证明了新提出的结构是稳定的。GeTeP单层的泊松比在0.16 - 0.18范围内，杨氏模量在40.16 - 43.74 N/m范围内。被取代的Te原子增强了sp轨道，从而加强了σ键，因此GeTeP单层的厚度小于单层GeP的厚度。GeTeP单层具有1.85 eV的间接带隙，可通过应变使其变窄。从 - 2%到 - 4%的压缩带隙将电子结构从间接带隙转变为直接带隙。应变还可以提高可见光区域的光吸收率（在平衡时为2 - 3×10⁵ cm⁻¹）。GeTeP单层具有适合析氢的带隙以及合适的价带顶和导带底位置。在4%及更高的应变速率下，价带顶和导带底仍处于适合产氢的位置。GeTeP单层的另一个优点是其电荷载流子迁移率非常高。最高电子迁移率为1301.47 cm²/V·s，最高空穴迁移率为28627.24 cm²/V·s，这远高于单层GeP中的迁移率。GeTeP单层在光催化应用方面具有优势，有必要对该材料进行进一步研究。
