Edge‐Epitaxial Growth of 2D NbS2‐WS2 Lateral Metal‐Semiconductor Heterostructures

• Published in: Advanced materials (Weinheim) Vol. 30; no. 40; pp. e1803665 - n/a
• Main Authors: Zhang, Yu, Yin, Lei, Chu, Junwei, Shifa, Tofik Ahmed, Xia, Jing, Wang, Feng, Wen, Yao, Zhan, Xueying, Wang, Zhenxing, He, Jun
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 04-10-2018
• Subjects: Chemical vapor deposition; controllable growth; Electric contacts; Electrical junctions; Electrons; Epitaxial growth; Heterostructures; Materials science; metallic transition metal dichalcogenides (TMDs); metal‐semiconductor heterostructures; Modulation; NbS2‐WS2 heterostructures; Organic chemistry; P-n junctions; Photoluminescence; Sapphire; Substrates; Synthesis; Transmission electron microscopy
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.201803665

2D metal‐semiconductor heterostructures based on transition metal dichalcogenides (TMDs) are considered as intriguing building blocks for various fields, such as contact engineering and high‐frequency devices. Although, a series of p–n junctions utilizing semiconducting TMDs have been constructed hitherto, the realization of such a scheme using 2D metallic analogs has not been reported. Here, the synthesis of uniform monolayer metallic NbS2 on sapphire substrate with domain size reaching to a millimeter scale via a facile chemical vapor deposition (CVD) route is demonstrated. More importantly, the epitaxial growth of NbS2‐WS2 lateral metal‐semiconductor heterostructures via a “two‐step” CVD method is realized. Both the lateral and vertical NbS2‐WS2 heterostructures are achieved here. Transmission electron microscopy studies reveal a clear chemical modulation with distinct interfaces. Raman and photoluminescence maps confirm the precisely controlled spatial modulation of the as‐grown NbS2‐WS2 heterostructures. The existence of the NbS2‐WS2 heterostructures is further manifested by electrical transport measurements. This work broadens the horizon of the in situ synthesis of TMD‐based heterostructures and enlightens the possibility of applications based on 2D metal‐semiconductor heterostructures.
The edge‐epitaxial growth of 2D (two‐dimensional) NbS2‐WS2 metal‐semiconductor heterostructures is demonstrated. Both lateral and vertical NbS2‐WS2 heterostructures are achieved. The synthesis of monolayer NbS2 with domain size reaching to a millimeter scale is also realized. This work broadens the horizon of the synthesis of heterostructures and enlightens the possibility of applications based on metal‐semiconductor heterostructures.