Size and temperature effect on Young's modulus of silicon nanowires

This paper reports quantitative measurements of the Young's modulus of 78 silicon nanowires (SiNWs) with diameters ranging from 20 to 160 nm over a temperature range from room temperature to 600 K. The SiNWs were synthesized using the vapor–liquid–solid growth process, with a ⟨112⟩ growth direction and a single twin boundary running parallel to the nanowire axis. Uniaxial tensile tests were performed at multiple temperatures using a microelectromechanical system-based testing platform inside a transmission electron microscope. A total of 200 Young's modulus measurements were obtained, as most SiNWs were tested at multiple temperatures. At each temperature, the Young's modulus decreases systematically with decreasing nanowire diameter. Furthermore, the Young's modulus exhibits an approximately linear decrease with increasing temperature, and the magnitude of this temperature dependence becomes more pronounced as the nanowire diameter decreases. These results reveal the coupled effects of size and temperature on the elastic properties of SiNWs and provide a comprehensive experimental dataset for understanding and modeling the thermomechanical behavior of semiconductor nanostructures.