Defects controlled hole doping and multivalley transport in SnSe single crystals

• DOI: 10.1038/s41467-017-02566-1
• Publication Date: 2017-12-28T17:13:52Z
• Authors: Zhen Wang; Congcong Fan; Zhixuan Shen; Chenqiang Hua; Qifeng Hu; Feng Sheng; Yunhao Lu; Hanyan Fang; Zhizhan Qiu; Jiong Lu; Zhengtai Liu; Wanling Liu; Yaobo Huang; Zhu-An Xu; D. W. Shen; Yi Zheng
• Keywords: crystal structure; energy dissipation; spectroscopy; surface property; engineering; Science; FOS: Physical sciences; anisotropy; electronic equipment; 01 natural sciences; Article; crystal; crystallography; Condensed Matter - Materials Science; quantum mechanics; Q; Materials Science (cond-mat.mtrl-sci); oscillation; 540; 0104 chemical sciences; tin derivative; selenium derivative; performance assessment; transport process; strength

SnSe is a promising thermoelectric material with record-breaking figure of merit. However, to date comprehensive understanding the electronic structure and most critically, self-hole-doping mechanism in still absent. Here we report highly anisotropic investigated by angle-resolved photoemission spectroscopy, which unique pudding-mould-shaped valence band quasi-linear energy dispersion revealed. We prove that p-type doping extrinsically controlled local phase segregation SnSe2 microdomains via interfacial charge transferring. The multivalley nature pudding-mould manifested quantum transport crystallographic axis-dependent weak localisation exotic non-saturating negative magnetoresistance. Strikingly, oscillations also reveal 3D Fermi surface unusual interlayer coupling strength p-SnSe, individual monolayers are interwoven peculiar point dislocation defects. Our results suggest defect engineering may provide versatile routes improving performance family.