材料科学
纳米线
成核
半导体
晶界
位错
应变工程
纳米技术
退火(玻璃)
光电子学
硅
复合材料
微观结构
化学
有机化学
作者
Zhiyuan Sun,Chunyi Huang,Jinglong Guo,Jason T. Dong,Robert F. Klie,Lincoln J. Lauhon,David N. Seidman
出处
期刊:ACS Nano
[American Chemical Society]
日期:2019-02-26
卷期号:13 (3): 3730-3738
被引量:7
标识
DOI:10.1021/acsnano.9b01231
摘要
Strain engineering of semiconductors is used to modulate carrier mobility, tune the energy bandgap, and drive growth of self-assembled nanostructures. Understanding strain-energy relaxation mechanisms including phase transformations, dislocation nucleation and migration, and fracturing is essential to both exploit this degree of freedom and avoid degradation of carrier lifetime and mobility, particularly in prestrained electronic devices and flexible electronics that undergo large changes in strain during operation. Raman spectroscopy, high-resolution transmission electron microscopy, and electron diffraction are utilized to identify strain-energy release mechanisms of bent diamond-cubic silicon (Si) and zinc-blende GaAs nanowires, which were elastically strained to >6% at room temperature and then annealed at an elevated temperature to activate relaxation mechanisms. High-temperature annealing of bent Si-nanowires leads to the nucleation, glide, and climb of dislocations, which align themselves to form grain boundaries, thereby reducing the strain energy. Herein, Si nanowires are reported to undergo polygonization, which is the formation of polygonal-shaped grains separated by grain boundaries consisting of aligned edge dislocations. Furthermore, strain is shown to drive dopant diffusion. In contrast to the behavior of Si, GaAs nanowires release strain energy by forming nanocracks in regions of tensile strain due to the weakening of As-bonds. These insights into the relaxation behavior of highly strained crystals can inform the design of nanoelectronic devices and provide guidance on mitigating degradation.
科研通智能强力驱动
Strongly Powered by AbleSci AI