Graphene–Silicon Device for Visible and Infrared Photodetection
| Autor: | Mohammad Bagher Askari, Antonio Di Bartolomeo, Aniello Pelella, Giuseppe Luongo, Alessandro Grillo, Enver Faella |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
heterojunction Band gap Schottky barrier FOS: Physical sciences Gr-Si junction Applied Physics (physics.app-ph) Responsivity Schottky diode graphene infrared noise equivalent power photodetector quantum efficiency responsivity visible Mesoscale and Nanoscale Physics (cond-mat.mes-hall) General Materials Science Noise-equivalent power Diode Condensed Matter - Mesoscale and Nanoscale Physics business.industry Heterojunction Physics - Applied Physics Optoelectronics Quantum efficiency business Research Article |
| Zdroj: | ACS Applied Materials & Interfaces |
| ISSN: | 1944-8252 1944-8244 |
| DOI: | 10.1021/acsami.1c12050 |
| Popis: | The fabrication of a graphene–silicon (Gr-Si) junction involves the formation of a parallel metal–insulator–semiconductor (MIS) structure, which is often disregarded but plays an important role in the optoelectronic properties of the device. In this work, the transfer of graphene onto a patterned n-type Si substrate, covered by Si3N4, produces a Gr-Si device, in which the parallel MIS consists of a Gr-Si3N4-Si structure surrounding the Gr-Si junction. The Gr-Si device exhibits rectifying behavior with a rectification ratio up to 104. The investigation of its temperature behavior is necessary to accurately estimate the Schottky barrier height (SBH) at zero bias, φb0 = 0.24 eV, the effective Richardson’s constant, A* = 7 × 10–10 AK–2 cm–2, and the diode ideality factor n = 2.66 of the Gr-Si junction. The device is operated as a photodetector in both photocurrent and photovoltage mode in the visible and infrared (IR) spectral regions. A responsivity of up to 350 mA/W and an external quantum efficiency (EQE) of up to 75% are achieved in the 500–1200 nm wavelength range. Decreases in responsivity to 0.4 mA/W and EQE to 0.03% are observed above 1200 nm, which is in the IR region beyond the silicon optical band gap, in which photoexcitation is driven by graphene. Finally, a model based on two parallel and opposite diodes, one for the Gr-Si junction and the other for the Gr-Si3N4-Si MIS structure, is proposed to explain the electrical behavior of the Gr-Si device. |
| Databáze: | OpenAIRE |
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