Multilayer WS2 for low-power visible and near-infrared phototransistors

Aniello Pelella; Kimberly Intonti; Ofelia Durante; Arun Kumar; Loredana Viscardi; Sebastiano De Stefano; Paola Romano; Filippo Giubileo; Hazel Neill; Vilas Patil; Lida Ansari; Brendan Roycroft; Paul K Hurley; Farzan Gity; Antonio Di Bartolomeo

doi:10.1186/s11671-024-04000-0

Multilayer WS₂ for low-power visible and near-infrared phototransistors

Discov Nano. 2024 Mar 25;19(1):57. doi: 10.1186/s11671-024-04000-0.

Authors

Aniello Pelella¹, Kimberly Intonti^{2

3}, Ofelia Durante², Arun Kumar², Loredana Viscardi^{2

3}, Sebastiano De Stefano², Paola Romano^{1

3}, Filippo Giubileo³, Hazel Neill⁴, Vilas Patil⁴, Lida Ansari⁴, Brendan Roycroft⁴, Paul K Hurley^{4

5}, Farzan Gity⁴, Antonio Di Bartolomeo^{6

7}

Affiliations

¹ Department of Science and Technology, University of Sannio, Via De Sanctis 59/A, 82100, Benevento, Italy.
² Department of Physics "E. R. Caianiello", University of Salerno, Via Giovanni Paolo II, 84084, Fisciano, Salerno, Italy.
³ CNR-SPIN Salerno, Via Giovanni Paolo II, 84084, Fisciano, Italy.
⁴ Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, T12 R5CP, Ireland.
⁵ School of Chemistry, University College Cork, Cork, Ireland.
⁶ Department of Physics "E. R. Caianiello", University of Salerno, Via Giovanni Paolo II, 84084, Fisciano, Salerno, Italy. adibartolomeo@unisa.it.
⁷ CNR-SPIN Salerno, Via Giovanni Paolo II, 84084, Fisciano, Italy. adibartolomeo@unisa.it.

Abstract

Mechanically exfoliated multilayer WS₂ flakes are used as the channel of field effect transistors for low-power photodetection in the visible and near-infrared (NIR) spectral range. The electrical characterization as a function of the temperature reveals devices with n-type conduction and slightly different Schottky barriers at the drain and source contacts. The WS₂ phototransistors can be operated in self-powered mode, yielding both a current and a voltage when exposed to light. The spectral photoresponse in the visible and the NIR ranges shows a high responsivity (4.5 μA/W) around 1250 nm, making the devices promising for telecommunication applications.