Qi Jingshan, Shi Daning, Jia Jianming
Department of Physics, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China.
Nanotechnology. 2008 Oct 29;19(43):435707. doi: 10.1088/0957-4484/19/43/435707. Epub 2008 Sep 22.
The electronic and elastic properties of [0001] ZnO nanobelts with different lateral dimensions have been studied by employing first-principles approaches. We find that the surface effects are dominant for the energetic stability of the nanobelt, while the quantum confinement effect plays an important role in the band gaps of the nanobelts. More importantly, we show that the different dominant surfaces of nanobelts have important influences on the band gaps, but minimal effects on the size dependence of the Young's modulus. The Young's modulus is larger than the bulk value and decreases with the increase of the square root of the cross-sectional area of the nanobelts. Finally, we find that the continuum-based model proposed for the Young's modulus of nanostructures is applicable for ZnO nanowires of 10-200 nm diameter, but not for ultrathin nanowires and nanobelts.
通过采用第一性原理方法，研究了具有不同横向尺寸的[0001] ZnO纳米带的电学和弹性性质。我们发现，表面效应对于纳米带的能量稳定性起主导作用，而量子限制效应在纳米带的带隙中起重要作用。更重要的是，我们表明纳米带不同的主导表面对带隙有重要影响，但对杨氏模量的尺寸依赖性影响极小。杨氏模量大于体材料值，并随着纳米带横截面积平方根的增加而减小。最后，我们发现为纳米结构杨氏模量提出的基于连续介质的模型适用于直径为10 - 200 nm的ZnO纳米线，但不适用于超薄纳米线和纳米带。
