Best Paper Award at MIPRO 2020
The paper ‘Plasmonic Enhanced Photodetectors for Near Infra-red Light Detection’ has been awarded as one of the 3 best papers of the MEET / Microelectronics, Electronics and Electronic Technology Conference, during the 43rd mipro (International Convention on Information, Communication and Technology) held in Opatija, Croatia, from September 28 to October 2, 2020.
The paper reported the possibility of improving the performances of silicon Single Photon Avalanche Diodes (SPADs) made at FBK also in an interval of light wavelengths (near-infrared, NIR) where usually the absorbance of the devices is rather poor.
In fact, SPAD’s are usually able to detect single photons in the visible part of the spectrum with high detection efficiency and high timing resolution. They can also be arranged in extended arrays as Silicon Photomultipliers (SiPM), providing both single-photon counting sensitivity and fast responsivity in large-area detectors. However, the performance of these devices for the detection of NIR photons is hindered by the limited Si absorption coefficient, resulting in absorption depths much larger than the typical active thickness of Si SPADs and SiPMs (10-100 µm against µm) and thus in a poor detection for most applications. In the paper, the exploitation of Surface Plasmon Polaritrons (SPP) was used to convert light in modes highly-confined in the active thickness of the devices to enhance the absorption of NIR photons. In particular, the integration of silver plasmonic nanostructures on the active area of test photodiodes allowed a quantum efficiency higher than 8%, that is an enhancement > 50% with respect to devices without these nanostructures. The results are promising for the application of SPADs to applications like light detection and ranging (LiDAR) for autonomous automotive and 3D-ranging imaging. The work was carried out within the ATTRACT_PlaSiPM project as a collaboration between FBK, the Instituto de Microelectrónica de Barcelona – Centro Nacional de Microelectrónica of Barcelona and the University of Padua. The paper was presented by D. Giubertoni and was coauthored by researchers from both MNF and IRIS unit of CMM: G. Paternoster, F. Acerbi, A. Cian, A. Gola, E. Scattolo and P. Bellutti.