|SIGNORELLI FABIO||Cycle: XXXIV |
Tutor: FIORINI CARLO ETTORE
Advisor: TOSI ALBERTO Major Research topic
:Single-Photon Avalanche Diodes in InGaAs/InP and micro-crystal heterostructuresAbstract:
The aim of this doctoral research project is to model, design, fabricate and characterize Single-Photon Avalanche Diodes (SPADs) both in consolidated and emerging technologies.
New InGaAs/InP SPADs will be developed by optimizing the design of the heterostructure, the growth and fabrication conditions and the layout, with the aim of strongly reducing both dark count rate and afterpulsing effects, while enhancing the photon detection efficiency, especially at 1550 nm.
With a ground-breaking approach, a novel growth and fabrication process (called vertical heteroepitaxy) will be exploited for developing new single-photon detectors. This process makes possible to exploit the patterning of conventional Si substrate to attain the self-assembly of epitaxial micro-crystals elongated in the vertical direction, with structural and electronic properties unparalleled by conventional epitaxial growth. New SPAD-based single-photon detectors will exploit vertical micro-crystal heterostructures fabricated in silicon, germanium and GaAs/AlGaAs quantum wells, in order to extend their sensitivity from visible (350 - 900 nm) to NIR (800 - 1800 nm) and MIR (5 - 10 μm) spectral regions.