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Graphene Schottky Junction on Pillar Patterned Silicon Substrate
2019, Luongo, Giuseppe, Grillo, Alessandro, Giubileo, Filippo, Iemmo, Laura, Lukosius, Mindaugas, Chavarin, Carlos Alvarado, Wenger, Christian, Di Bartolomeo, Antonio
A graphene/silicon junction with rectifying behaviour and remarkable photo-response was fabricated by transferring a graphene monolayer on a pillar-patterned Si substrate. The device forms a 0.11 eV Schottky barrier with 2.6 ideality factor at room temperature and exhibits strongly biasand temperature-dependent reverse current. Below room temperature, the reverse current grows exponentially with the applied voltage because the pillar-enhanced electric field lowers the Schottky barrier. Conversely, at higher temperatures, the charge carrier thermal generation is dominant and the reverse current becomes weakly bias-dependent. A quasi-saturated reverse current is similarly observed at room temperature when the charge carriers are photogenerated under light exposure. The device shows photovoltaic effect with 0.7% power conversion efficiency and achieves 88 A/W photoresponsivity when used as photodetector. © 2019 by the authors.
Quantitative protein sensing with germanium THz-antennas manufactured using CMOS processes
2022, Hardt, Elena, Chavarin, Carlos Alvarado, Gruessing, Soenke, Flesch, Julia, Skibitzki, Oliver, Spirito, Davide, Vita, Gian Marco, Simone, Giovanna De, Masi, Alessandra di, You, Changjiang, Witzigmann, Bernd, Piehler, Jacob, Capellini, Giovanni
The development of a CMOS manufactured THz sensing platform could enable the integration of state-of-the-art sensing principles with the mixed signal electronics ecosystem in small footprint, low-cost devices. To this aim, in this work we demonstrate a label-free protein sensing platform using highly doped germanium plasmonic antennas realized on Si and SOI substrates and operating in the THz range of the electromagnetic spectrum. The antenna response to different concentrations of BSA shows in both cases a linear response with saturation above 20 mg/mL. Ge antennas on SOI substrates feature a two-fold sensitivity as compared to conventional Si substrates, reaching a value of 6 GHz/(mg/mL), which is four-fold what reported using metal-based metamaterials. We believe that this result could pave the way to a low-cost lab-on-a-chip biosensing platform.