Multimodal Nanoscopic Study of Atomic Diffusion and Related Localized Optoelectronic Response of WS2/MoS2 Lateral Heterojunctions
| Autor: | Yijie Zeng, Hong-Wei Lu, Weitao Su, Jiaqi Shao, Fei Chen |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Kelvin probe force microscope
Materials science Photoluminescence business.industry Heterojunction 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Atomic diffusion symbols.namesake symbols Optoelectronics General Materials Science van der Waals force 0210 nano-technology Raman spectroscopy business Nanoscopic scale Volta potential |
| Zdroj: | ACS Applied Materials & Interfaces. 13:20361-20370 |
| ISSN: | 1944-8252 1944-8244 |
| Popis: | The atomic diffusion in transition metal dichalcogenides (TMDs) van der Waals heterojunctions (HJs) strongly modifies their optoelectronic properties in the nanoscale. However, probing such localized properties challenges the spatial resolution and the sensitivity of a variety of analytic tools. Herein, a multimodal nanoscopy (based on tip enhanced Raman spectroscopy (TERS) and photoluminescence (TEPL)) combined with the Kelvin probe force microscopy (KPFM) method was used to probe such nanoscale localized optoelectronic properties induced by atomic diffusion. Chemical vapor deposition (CVD)-grown lateral bilayer (2L) WS2/MoS2 HJs were imaged with a spatial resolution better than 40 nm via TERS and TEPL mapping by using intrinsic Raman and photoluminescence (PL) peaks. The contact potential difference (CPD), capacitance, and PL variation in a nanoscale vicinity of the HJ interface can be correlated to the local stoichiometry variation determined by TERS. The diffusion coefficients of W and Mo were obtained to be ∼0.5 × 10-12 and ∼1 × 10-12 cm2/s, respectively, by using Fick's second law. The obtained results would be useful to further understand the localized optoelectronic response of the TMDs HJs. |
| Databáze: | OpenAIRE |
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