Tunable photodetectors via in situ thermal conversion of TiS3 to TiO2
In two-dimensional materials research, oxidation is usually considered as a common source for the degradation of electronic and optoelectronic devices or even device failure. However, in some cases a controlled oxidation can open the possibility to widely tune the band structure of 2D materials. In...
| Autores: | , , , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/209472 |
| Acceso en línea: | http://hdl.handle.net/10261/209472 |
| Access Level: | acceso abierto |
| Palabra clave: | 2D materials Photodetectors oxidation TiS3 TiO2 Raman spectroscopy DFT GW |
| Sumario: | In two-dimensional materials research, oxidation is usually considered as a common source for the degradation of electronic and optoelectronic devices or even device failure. However, in some cases a controlled oxidation can open the possibility to widely tune the band structure of 2D materials. In particular, we demonstrate the controlled oxidation of titanium trisulfide (TiS<sub>3</sub>), a layered semicon-ductor that has attracted much attention recently thanks to its quasi-1D electronic and optoelectron-ic properties and its direct bandgap of 1.1 eV. Heating TiS<sub>3</sub> in air above 300 °C gradually converts it into TiO<sub>2</sub>, a semiconductor with a wide bandgap of 3.2 eV with applications in photo-electrochemistry and catalysis. In this work, we investigate the controlled thermal oxidation of indi-vidual TiS<sub>3</sub> nanoribbons and its influence on the optoelectronic properties of TiS<sub>3</sub>-based photodetec-tors. We observe a step-wise change in the cut-off wavelength from its pristine value ~1000 nm to 450 nm after subjecting the TiS<sub>3</sub> devices to subsequent thermal treatment cycles. Ab-initio and many-body calculations confirm an increase in the bandgap of titanium oxysulfide (TiO<sub>2-x</sub>S<sub>x</sub>) when in-creasing the amount of oxygen and reducing the amount of sulfur. |
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