Arora Sandeep, Ahlawat Dharamvir Singh
Department of Physics, Chaudhary Devi Lal University, Sirsa, 125055, (Hry.), India.
Govt. Model Skt. Sen. Sec. School, Rania, 125076, Sirsa, India.
J Mol Model. 2024 Aug 13;30(9):309. doi: 10.1007/s00894-024-06103-y.
The aim of this work is to use first principles calculations to examine the effects of different mechanical strains on the optoelectronic and photocatalytic capabilities of the 2D/2D nanoheterostructure of AlN/GaN. By utilizing the lmBJ (Meta-GGA) and PBEsol (GGA) functional, the bandgap of the nanoheterostructure is calculated and found to be 4.89 eV and 3.24 eV. Simulated 2D AlN/GaN nanoheterostructure exhibits exceptional optical and electronic characteristics under applied biaxial tensile and compressive strains. The band gap changes from 4.89 to 3.77 eV, while the energy gap nature transitions from direct to indirect during tensile strain fluctuations of 0% to 8%. Strain is also found to have a significant effect on the optical absorption peaks. And a 0-8% rise in tensile strain causes the initial absorption peak of the 2D AlN/GaN nanoheterostructure to shift from 4.88 to 4.20 eV, which results in a 14% red shift in photon energy for every 2% change in strain. Furthermore, the optimum bandgap and band edge positions of the 2D AlN/GaN nanoheterostructure enable the water redox process to produce hydrogen and oxygen for wide range of pH. Thus, modification via strain may be an effective method for altering the optical as well as electronic characteristics of a 2D AlN/GaN nanoheterostructure, and this study may pave the way for new applications of this material in optoelectronic devices in the future.
In the current work, density functional theory is used to explore every attribute of the 2D AlN/GaN nanoheterostructure. To characterize the electronic exchange-correlation, we used the PBEsol functional. In order to prevent any interlayer contact between periodicity of images, a vacuum is produced along the z-direction of approximately 10 Å. To increase the precision of bandgap prediction, the electronic and optical characteristics were computed using the meta-GGA lmBJ functional. To account for interlayer van der Waals interactions, nanoheterostructure computations were performed using the DFT-D3 functional.
这项工作的目的是利用第一性原理计算来研究不同机械应变对AlN/GaN二维/二维纳米异质结构的光电和光催化能力的影响。通过使用lmBJ（元广义梯度近似）和PBEsol（广义梯度近似）泛函，计算出纳米异质结构的带隙分别为4.89电子伏特和3.24电子伏特。模拟的二维AlN/GaN纳米异质结构在施加双轴拉伸和压缩应变时表现出优异的光学和电子特性。在0%至8%的拉伸应变波动期间，带隙从4.89电子伏特变化到3.77电子伏特，而能隙性质从直接跃迁为间接。还发现应变对光吸收峰有显著影响。二维AlN/GaN纳米异质结构的拉伸应变每增加0 - 8%，其初始吸收峰就从4.88电子伏特移动到4.20电子伏特，这意味着应变每变化2%，光子能量就会发生14%的红移。此外，二维AlN/GaN纳米异质结构的最佳带隙和带边位置能够使水氧化还原过程在广泛的pH值范围内产生氢气和氧气。因此，通过应变进行改性可能是改变二维AlN/GaN纳米异质结构光学和电子特性的有效方法，并且这项研究可能为这种材料未来在光电器件中的新应用铺平道路。
在当前工作中，使用密度泛函理论来探究二维AlN/GaN纳米异质结构的各种属性。为了表征电子交换关联，我们使用了PBEsol泛函。为了防止图像周期性之间的任何层间接触，沿z方向产生了约10埃的真空。为了提高带隙预测的精度，使用元广义梯度近似lmBJ泛函计算电子和光学特性。为了考虑层间范德华相互作用，使用DFT - D3泛函进行纳米异质结构计算。
