Raval Dhara, Gupta Sanjeev K, Gajjar P N, Ahuja Rajeev
Department of Physics, University School of Sciences, Gujarat University, Ahmedabad, 380009, India.
Computational Materials and Nanoscience Group, Department of Physics and Electronics, St. Xavier's College, Ahmedabad, 380009, India.
Sci Rep. 2022 Feb 22;12(1):2964. doi: 10.1038/s41598-022-06142-6.
We studied the physical, electronic transport and optical properties of a unique pentagonal PdQ (Q = S, Se) monolayers. The dynamic stability of 2Dwrinkle like-PdQ is proven by positive phonon frequencies in the phonon dispersion curve. The optimized structural parameters of wrinkled pentagonal PdQ are in good agreement with the available experimental results. The ultimate tensile strength (UTHS) was calculated and found that, penta-PdS monolayer can withstand up to 16% (18%) strain along x (y) direction with 3.44 GPa (3.43 GPa). While, penta-PdSe monolayer can withstand up to 17% (19%) strain along x (y) dirrection with 3.46 GPa (3.40 GPa). It is found that, the penta-PdQ monolayers has the semiconducting behavior with indirect band gap of 0.94 and 1.26 eV for 2D-PdS and 2D-PdSe, respectively. More interestingly, at room temperacture, the hole mobilty (electron mobility) obtained for 2D-PdS and PdSe are 67.43 (258.06) cm V s and 1518.81 (442.49) cm V s, respectively. In addition, I-V characteristics of PdSe monolayer show strong negative differential conductance (NDC) region near the 3.57 V. The Shockly-Queisser (SQ) effeciency prameters of PdQ monolayers are also explored and the highest SQ efficeinciy obtained for PdS is 33.93% at -5% strain and for PdSe is 33.94% at -2% strain. The penta-PdQ exhibits high optical absorption intensity in the UV region, up to 4.04 × 10 (for PdS) and 5.28 × 10 (for PdSe), which is suitable for applications in optoelectronic devices. Thus, the ultrathin PdQ monolayers could be potential material for next-generation solar-cell applications and high performance nanodevices.
我们研究了一种独特的五角形PdQ（Q = S，Se）单层的物理、电子输运和光学性质。二维皱纹状PdQ的动态稳定性通过声子色散曲线中的正声子频率得到证明。皱纹状五角形PdQ的优化结构参数与现有实验结果吻合良好。计算了极限抗拉强度（UTHS），发现五边形PdS单层在x（y）方向上分别能承受高达16%（18%）的应变，其极限抗拉强度为3.44 GPa（3.43 GPa）。而五边形PdSe单层在x（y）方向上能承受高达17%（19%）的应变，其极限抗拉强度为3.46 GPa（3.40 GPa）。研究发现，五边形PdQ单层具有半导体行为，二维PdS和二维PdSe的间接带隙分别为0.94和1.26 eV。更有趣的是，在室温下，二维PdS和PdSe的空穴迁移率（电子迁移率）分别为67.43（258.06）cm² V⁻¹ s⁻¹和1518.81（442.49）cm² V⁻¹ s⁻¹。此外，PdSe单层的I-V特性在3.57 V附近显示出强负微分电导（NDC）区域。还探索了PdQ单层 的肖克利-奎塞尔（SQ）效率参数，PdS在-5%应变下获得的最高SQ效率为33.93%，PdSe在-2%应变下获得的最高SQ效率为33.94%。五边形PdQ在紫外区域表现出高光学吸收强度，对于PdS高达4.04×10⁵，对于PdSe高达5.28×10⁵，这适用于光电器件应用。因此，超薄PdQ单层可能是下一代太阳能电池应用和高性能纳米器件的潜在材料。
