We report vertically-illuminated, resonant cavity enhanced, graphene-Si Schottky photodetectors (PDs) operating at 1550nm. These exploit internal photoemission at the graphene-Si interface. To obtain spectral selectivity and enhance responsivity, the PDs are integrated with an optical cavity, resulting in multiple reflections at resonance, and enhanced absorption in graphene. Our devices have wavelength-dependent photoresponse with external (internal) responsivity~20mA/W (0.25A/W). The spectral-selectivity may be further tuned by varying the cavity resonant wavelength. Our devices pave the way for developing high responsivity hybrid graphene-Si free-space illuminated PDs for free-space optical communications, coherence optical tomography and light-radars
@article{arxiv.1708.07102,
title = {Vertically-Illuminated, Resonant-Cavity-Enhanced, Graphene-Silicon Schottky Photodetectors},
author = {M. Casalino and U. Sassi and I. Goykhman and A. Eiden and E. Lidorikis and S. Milana and D. De Fazio and F. Tomarchio and M. Iodice and G. Coppola and A. C. Ferrari},
journal= {arXiv preprint arXiv:1708.07102},
year = {2018}
}