Description of the activity
The integration of innovative two-dimensional materials such as graphene with established silicon (Si) technology is giving new life to the complex field called Silicon Photonics. New emerging 2D materials like graphene have recently opened new perspectives in the field of the near-infrared (NIR) Si-based photodetectors (PDs), historically hindered by the Si transparency at wavelengths above 1.1 μm.
A PD based on a graphene/Si Schottky junction incorporated into a Fabry-Peròt resonant microcavity operating at the telecom wavelength of 1550 nm has been developed in collaboration with the Cambridge Graphene Centre. This device showed a negligible series resistance, a Schottky barrier of ~460 meV and a promising responsivity of ~20 mA/W at -10V.
The development of advanced versions of these devices is still in progress. In collaboration with IMM-BO (CNR), by H2020 European funding (ATTRACT Grant: 777222), the GrapheNeapolis group of ISASI-NA is working on a resonant PD where a graphene layer is placed in the middle of a high-finesse Fabry-Pèrot microcavity constituted by both crystalline and hydrogenated amorphous silicon layers . Preliminary measurements show a responsivity of 0.3A/W at 123nW of incoming optical power of 1550nm.
National and International Collaborations
CNR – National Council of Researches (Institute of Sciences and Technologies for Sustainable Energy and Mobility – STEMS, Institute for Microelectronics and Microsystems – IMM)
University of Campania “Luigi Vanvitelli” – Dep. Mathematics e Physics
University “Mediterranea” of Reggio Calabria
Cambridge Graphene Centre
Clean-room: Photolitography, thermal evaporation, thermal oxidation, wet etching, Reactive Ion Etching (RIE), Plasma enhanced chemical vapour deposition (PECVD).
Electrical characterization: two and four points measurements;
Optical characterization: NIR tunable laser (1520-1620nm), 2micron laser, chopper, lock-in measurements, transimpedance amplifier, oscilloscope, microscope, optical modulator Bias-T, micro- nano-positioner, photodetectors.