Super deformability and thermoelectricity of bulk γ-InSe single crystals*
Bin Zhang, Hong Wu, Kunling Peng, Xingchen Shen, Xiangnan Gong, Sikang Zheng, Lu Xu, Guoyu Wang, Xiaoyuan Zhou
Abstract
Indium selenide, a III–V group semiconductor with layered structure, attracts intense attention in various photoelectric applications, due to its outstanding properties. Here, we report super deformability and thermoelectricity of γ -InSe single crystals grown by modified Bridgeman method. The crystal structure of InSe is studied systematically by transmission electron microscopy methods combined with x-ray diffraction and Raman spectroscopy. The predominate phase of γ -InSe with dense stacking faults and local multiphases is directly demonstrated at atomic scale. The bulk γ -InSe crystals demonstrate surprisingly high intrinsic super deformative ability which is highly pliable with bending strains exceeding 12.5% and 264% extension by rolling. At the meantime, InSe also possesses graphite-like features which is printable, writable, and erasable. Finally, the thermoelectric properties of γ -InSe bulk single crystals are preliminary studied and thermal conductivity can be further reduced via bending-induced defects. These findings will enrich the knowledge of structural and mechanical properties’ flexibility of InSe and shed lights on the intrinsic and unique mechanical properties of InSe polytypes.