Epitaxy of NiTe2 on WS2 for the p-Type Schottky Contact and Increased Photoresponse
Epitaxy of NiTe2 on WS2 for the p-Type Schottky Contact and Increased Photoresponse
复制标题
NiTe2 在 WS2 上的外延可形成 p 型肖特基接触并增强光响应
DOI：
10.1021/acsami.2c06968
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Qinglin Zhang
中科院分区：
文献类型：
--
作者：
Zhuodong Qi;Xiaokun Zhai;Xiaohong Jiang;Xing Xu;Chao Fan;Lei Shen;Qin Xiao;Sha Jiang;Qi Deng;Hongjun Liu;Fangli Jing;Qinglin Zhang
Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have great potential applications in the electronic and optoelectronic devices. Nevertheless, due to the difficulty in the efficient doping of atomic-thickness TMDCs or Fermi level pinning (FLP) effects at the metal/semiconductor interface, most TMDC devices exhibit the n-type conduction polarity, which significantly limits their functional applications based on the p–n junction. Here, 2D semi-metal NiTe2nanosheets were epitaxially grown on the WS2monolayer by a two-step chemical vapor deposition route. The microstructure and optical characterizations confirm that the vertically stacked NiTe2/WS2heterostructures are formed by van der Waals epitaxy. Interestingly, p-type WS2field-effect transistors can be obtained with the hole mobility of ∼4.22 cm2/V·s, when the epitaxial NiTe2sheets act as the source/drain electrodes. This is attributed to the decreased FLP effect and hence the low potential barrier for holes at the van der Waals contacts. Furthermore, the photodetectors based on the heterostructures show a 2 orders of magnitude increase in the switch ratio, responsivity, and detectivity and a 1 order of magnitude increase in the rise and decay speeds relative to those based on pristine WS2. This work paves the way to realize the p-type contact for monolayer WS2with significantly enhanced optoelectronic performance.
