Scalable Production of a Few-Layer MoS2/WS2 Vertical Heterojunction Array and Its Application for Photodetectors

详细信息    查看全文

• 作者：Yunzhou Xue ; Yupeng Zhang ; Yan Liu ; Hongtao Liu ; Jingchao Song ; Joice Sophia ; Jingying Liu ; Zaiquan Xu ; Qingyang Xu ; Ziyu Wang ; Jialu Zheng ; Yunqi Liu ; Shaojuan Li ; Qiaoliang Bao
• 刊名：ACS Nano
• 出版年：2016
• 出版时间：January 26, 2016
• 年：2016
• 卷：10
• 期：1
• 页码：573-580
• 全文大小：510K
• ISSN：1936-086X

文摘

Vertical heterojunctions of two two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted considerable attention recently. A variety of heterojunctions can be constructed by stacking different TMDs to form fundamental building blocks in different optoelectronic devices such as photodetectors, solar cells, and light-emitting diodes. However, these applications are significantly hampered by the challenges of large-scale production of van der Waals stacks of atomically thin materials. Here, we demonstrate scalable production of periodic patterns of few-layer WS₂, MoS₂, and their vertical heterojunction arrays by a thermal reduction sulfurization process. In this method, a two-step chemical vapor deposition approach was developed to effectively prevent the phase mixing of TMDs in an unpredicted manner, thus affording a well-defined interface between WS₂ and MoS₂ in the vertical dimension. As a result, large-scale, periodic arrays of few-layer WS₂, MoS₂, and their vertical heterojunctions can be produced with desired size and density. Photodetectors based on the as-produced MoS₂/WS₂ vertical heterojunction arrays were fabricated, and a high photoresponsivity of 2.3 A·W^–1 at an excitation wavelength of 450 nm was demonstrated. Flexible photodetector devices using MoS₂/WS₂ heterojunction arrays were also demonstrated with reasonable signal/noise ratio. The approach in this work is also applicable to other TMD materials and can open up the possibilities of producing a variety of vertical van der Waals heterojunctions in a large scale toward optoelectronic applications.