Growth of uniform MoS2 layers on free-standing GaN semiconductor for vertical heterojunction device application
| Autor: | Mandar Shinde, Masaki Tanemura, Rakesh D. Mahyavanshi, Pradeep Desai, Ajinkya K. Ranade, Golap Kalita, Bhagyashri Todankar |
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| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Materials science business.industry Scanning electron microscope Heterojunction Gallium nitride Condensed Matter Physics 01 natural sciences Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials chemistry.chemical_compound symbols.namesake Semiconductor chemistry X-ray photoelectron spectroscopy 0103 physical sciences symbols Optoelectronics Wafer Electrical and Electronic Engineering Raman spectroscopy business Diode |
| Zdroj: | Journal of Materials Science: Materials in Electronics. 31:2040-2048 |
| ISSN: | 1573-482X 0957-4522 |
| Popis: | The feasibility of van der Waals (VdW) heteroepitaxy of molybdenum disulphide (MoS2) layers on gallium nitride (GaN) semiconductor has attracted significant interest in heterojunction optoelectronic device applications. Here, we report on the growth of uniform MoS2 layers on free-standing GaN semiconductor for vertical heterojunction device application. A uniform MoS2 layer was directly grown on the n-type GaN wafer by sulphurization process of molybdenum oxide thin layer. Raman and scanning electron microscopy (SEM) analyses showed homogenous growth of the few-layers MoS2 forming a continuous film, considering the suitability of GaN semiconductor substrate. The fabricated MoS2/GaN vertical heterojunction showed excellent rectifying diode characteristics with a photovoltaic photoresponsivity under monochromatic light illumination. The X-ray photoelectron spectroscopy (XPS) studies showed the conduction and valence band offset values are around 0.44 and 2.3 eV with type II band alignment in the fabricated heterojunction device. This will facilitate effective movement of photoexcited electrons across the MoS2–GaN junction, while a large valence band offset will prevent movement of holes towards the GaN, resulting in low recombination loss to obtain a photovoltage in the heterojunction device. Our study revealed the formation of large-area homogenous MoS2 layers on GaN wafer for vertical heterojunction device application. |
| Databáze: | OpenAIRE |
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