Nan Wang1,Jiangbin Wu1,Hefei Liu1,Xinghao Huang1,Hung-Yu Chen1,Jiahui Ma1,Hangbo Zhao1,Han Wang1
University of Southern California1
Nan Wang1,Jiangbin Wu1,Hefei Liu1,Xinghao Huang1,Hung-Yu Chen1,Jiahui Ma1,Hangbo Zhao1,Han Wang1
University of Southern California1
Tin indium phosphate (SnIP) is a quasi-one-dimensional inorganic double helical van der Waals semiconductor consisting of two atomic helical chains twining around each other along the axis of the helix at the atomic scale. Here, we experimentally discovered the extraordinary mechanical properties of SnIP. Confirmed through both nanomechanical bending measurements and the Brillouin scattering spectroscopy, this unique double helical structure possesses the smallest Young’s modulus (~13.6 GPa) among any known stable inorganic materials and is even comparable with many polymers. Furthermore, the relatively easy slippage between neighboring double helices coupled through van der Waals interactions resulted in a surprisingly large elastic (>27%) and plastic (>60%) bending strain, conferring SnIP the highest flexibility and deformability among all known semiconducting materials. This discovery represents a major breakthrough in materials science that not only sets new records for key mechanical properties of inorganic materials, but also advances the understanding of this unique class of double helical van der Waals crystals with application potentials in a broad range of nanomechanics and nanoelectronics disciplines.