Large area growth and electrical properties of p-type WSe2 atomic layers
| Autor: | Xiangfeng Duan, Yu Huang, Hailong Zhou, Yu Chen, Jonathan C. Shaw, Xiaoqing Huang, Chen Wang, Zhaoyang Lin, Yuan Liu, Rui Cheng, Nathan O. Weiss |
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| Rok vydání: | 2015 |
| Předmět: |
Letter
Materials science large area growth Bioengineering Nanotechnology 02 engineering and technology Chemical vapor deposition 010402 general chemistry 01 natural sciences chemistry.chemical_compound field effect transistor Transition metal Monolayer Tungsten diselenide tungsten diselenide General Materials Science Nanoscience & Nanotechnology business.industry Mechanical Engineering General Chemistry Tungsten Compounds semiconductor 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Semiconductor chemistry Semiconductors layered materials Optoelectronics Direct and indirect band gaps Field-effect transistor 0210 nano-technology business Layer (electronics) |
| Zdroj: | Nano letters, vol 15, iss 1 Nano Letters |
| Popis: | Transition metal dichacogenides represent a unique class of two-dimensional layered materials that can be exfoliated into single or few atomic layers. Tungsten diselenide (WSe(2)) is one typical example with p-type semiconductor characteristics. Bulk WSe(2) has an indirect band gap (∼ 1.2 eV), which transits into a direct band gap (∼ 1.65 eV) in monolayers. Monolayer WSe(2), therefore, is of considerable interest as a new electronic material for functional electronics and optoelectronics. However, the controllable synthesis of large-area WSe(2) atomic layers remains a challenge. The studies on WSe(2) are largely limited by relatively small lateral size of exfoliated flakes and poor yield, which has significantly restricted the large-scale applications of the WSe(2) atomic layers. Here, we report a systematic study of chemical vapor deposition approach for large area growth of atomically thin WSe(2) film with the lateral dimensions up to ∼ 1 cm(2). Microphotoluminescence mapping indicates distinct layer dependent efficiency. The monolayer area exhibits much stronger light emission than bilayer or multilayers, consistent with the expected transition to direct band gap in the monolayer limit. The transmission electron microscopy studies demonstrate excellent crystalline quality of the atomically thin WSe(2). Electrical transport studies further show that the p-type WSe(2) field-effect transistors exhibit excellent electronic characteristics with effective hole carrier mobility up to 100 cm(2) V(-1) s(-1) for monolayer and up to 350 cm(2) V(-1) s(-1) for few-layer materials at room temperature, comparable or well above that of previously reported mobility values for the synthetic WSe(2) and comparable to the best exfoliated materials. |
| Databáze: | OpenAIRE |
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