Realization of vertical metal semiconductor heterostructures via solution phase epitaxy

• Main Authors: Wang, Xiaoshan, Wang, Zhiwei, Zhang, Jindong, Wang, Xiang, Zhang, Zhipeng, Wang, Jialiang, Zhu, Zhaohua, Li, Zhuoyao, Liu, Yao, Hu, Xuefeng, Qiu, Junwen, Hu, Guohua, Chen, Bo, Wang, Ning, He, Qiyuan, Chen, Junze, Yan, Jiaxu, Zhang, Wei, Hasan, Tawfique, Li, Shaozhou, Li, Hai, Zhang, Hua, Wang, Qiang, Huang, Xiao, Huang, Wei
• Other Authors: School of Materials Science & Engineering
• Format: Article
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Materials; Metal Semiconductor Heterostructures; Solution Phase Epitaxy
• Online Access: https://hdl.handle.net/10356/81389; http://hdl.handle.net/10220/47481
• Institution: Nanyang Technological University

The creation of crystal phase heterostructures of transition metal chalcogenides, e.g., the 1T/2H heterostructures, has led to the formation of metal/semiconductor junctions with low potential barriers. Very differently, post-transition metal chalcogenides are semiconductors regardless of their phases. Herein, we report, based on experimental and simulation results, that alloying between 1T-SnS2 and 1T-WS2 induces a charge redistribution in Sn and W to realize metallic Sn0.5W0.5S2 nanosheets. These nanosheets are epitaxially deposited on surfaces of semiconducting SnS2 nanoplates to form vertical heterostructures. The ohmic-like contact formed at the Sn0.5W0.5S2/SnS2 heterointerface affords rapid transport of charge carriers, and allows for the fabrication of fast photodetectors. Such facile charge transfer, combined with a high surface affinity for acetone molecules, further enables their use as highly selective 100 ppb level acetone sensors. Our work suggests that combining compositional and structural control in solution-phase epitaxy holds promises for solution-processible thin-film optoelectronics and sensors.