High photoresponse of individual WS₂ nanowire-nanoflake hybrid materials

van der Waals solids have been recognized as highly photosensitive materials that compete conventional Si and compound semiconductor based devices. While 2-dimensional nanosheets of single and multiple layers and 1-dimensional nanowires of molybdenum and tungsten chalcogenides have been studied, their nanostructured derivatives with complex morphologies are not explored yet. Here, we report on the electrical and photosensitive properties of WS₂ nanowire-nanoflake hybrid materials we developed lately. We probe individual hybrid nanostructured particles along the structure using focused ion beam deposited Pt contacts. Further, we use conductive atomic force microscopy to analyze electrical behavior across the nanostructure in the transverse direction. The electrical measurements are complemented by in situ laser beam illumination to explore the photoresponse of the nanohybrids in the visible optical spectrum. Photodetectors with responsivity up to ∼0.4 AW⁻¹ are demonstrated outperforming graphene as well as most of the other transition metal dichalcogenide based devices.

Asres Georgies Alene, Järvinen Topias, Lorite Gabriela S., Mohl Melinda, Pitkänen Olli, Dombovari Aron, Tóth Geza, Lloyd Spetz Anita, Vajtai Robert, Ajayan Pulickel M., Lei Sidong, Talapatra Saikat, Kordas Krisztian

A1 Journal article – refereed

Asres, G. A., Järvinen, T., Lorite, G. S., Mohl, M., Pitkänen, O., Dombovari, A., … Kordas, K. (2018). High photoresponse of individual WS2 nanowire-nanoflake hybrid materials. Applied Physics Letters, 112(23), 233103. https://doi.org/10.1063/1.5030490

https://doi.org/10.1063/1.5030490 http://urn.fi/urn:nbn:fi-fe2019052016095