Huan Hao, Chen Li, Ye Xiang
Department of Physics, Shanghai Normal University, Shanghai, 200234, People's Republic of China.
School of Arts and Sciences, MCPHS University, Boston, MA, 02115, USA.
Nanoscale Res Lett. 2017 Dec;12(1):178. doi: 10.1186/s11671-017-1952-9. Epub 2017 Mar 9.
First-principles density functional theory (DFT) simulations were carried out to study the strain dependence on the electronic and optical properties of cadmium selenide (CdSe) nanowires (NWs). The band structures, effective masses of electron and holes, dielectric properties, and other optical properties (such as extinction coefficient, optical reflectivity, and absorption coefficient) were calculated under both compressive and tensile uniaxial strains. Size-dependence was also discussed by comparing results among CdSe wires with various diameters. Simulation results show that an interesting band-switch behavior occurs at the valence bands regardless of size. The cause and the consequences of such band-switch behavior were also studied. Further strain dependence on corresponding electronic and optical properties were examined as well. Our results provide insights to possible mechanical tuning via strain on the electronic and optical properties of CdSe NWs.
开展了第一性原理密度泛函理论（DFT）模拟，以研究应变对硒化镉（CdSe）纳米线（NWs）电子和光学性质的依赖性。在压缩和拉伸单轴应变下，计算了能带结构、电子和空穴的有效质量、介电性质以及其他光学性质（如消光系数、光学反射率和吸收系数）。通过比较不同直径的CdSe纳米线的结果，还讨论了尺寸依赖性。模拟结果表明，无论尺寸如何，价带都会出现有趣的能带切换行为。还研究了这种能带切换行为的原因和后果。此外，还研究了应变对相应电子和光学性质的进一步依赖性。我们的结果为通过应变对CdSe纳米线的电子和光学性质进行可能的机械调谐提供了见解。
