Large Work Function Modulation of Monolayer MoS2 by Ambient Gases
| Autor: | Young Hee Lee, Young-Geun Roh, Hyangsook Lee, Hye Min Oh, Si Young Lee, Hye Yun Jeong, Gang Hee Han, JaeGwan Chung, Hyun Kim, Yeonsang Park, Jineun Kim, Sungwoo Hwang, Honggi Nam, Hyochul Kim, Un Jeong Kim |
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| Rok vydání: | 2016 |
| Předmět: |
Kelvin probe force microscope
Photocurrent Materials science business.industry Photoemission spectroscopy Graphene General Engineering General Physics and Astronomy Nanotechnology 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences law.invention law Monolayer Optoelectronics General Materials Science Work function Homojunction 0210 nano-technology business Diode |
| Zdroj: | ACS nano. 10(6) |
| ISSN: | 1936-086X |
| Popis: | Although two-dimensional monolayer transition-metal dichalcogenides reveal numerous unique features that are inaccessible in bulk materials, their intrinsic properties are often obscured by environmental effects. Among them, work function, which is the energy required to extract an electron from a material to vacuum, is one critical parameter in electronic/optoelectronic devices. Here, we report a large work function modulation in MoS2 via ambient gases. The work function was measured by an in situ Kelvin probe technique and further confirmed by ultraviolet photoemission spectroscopy and theoretical calculations. A measured work function of 4.04 eV in vacuum was converted to 4.47 eV with O2 exposure, which is comparable with a large variation in graphene. The homojunction diode by partially passivating a transistor reveals an ideal junction with an ideality factor of almost one and perfect electrical reversibility. The estimated depletion width obtained from photocurrent mapping was ∼200 nm, which is much narrower than bulk semiconductors. |
| Databáze: | OpenAIRE |
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