Speaker
Dr
Giovanni Paternoster
(Fondazione Bruno Kessler)
Description
New high-density (HD) cell silicon photomultipliers (SiPM) for near-ultraviolet light detection have been recently produced at Fondazione Bruno Kessler. The NUV-HD SiPMs are an evolution of the standard NUV technology, based on a p-on-n junction and featuring peak detection efficiency in the region between 380 and 480 nm. With respect to the standard NUV SiPMs, the HD technology implements a new border structure, based on trenches, which provide both electrical and optical isolation of the single-photon avalanche diodes. This technology has been exploited to produce devices with small cells (from 30×30 μm2 down to 12×12 μm2) increasing at the same time the fill factor (FF), equal to 77% for the bigger cell and higher than 50% for the smallest one.
Thanks to the high FF, a photo-detection efficiency approaching 55% has been measured at 400 nm for the SiPM with 25×25 µm2 cell size with a dark count rate of less than 150 kHz/mm2 at maximum efficiency and 20°C. At the same time, the ability to reduce the cell size preserving FF leads to a proportional reduction of the gain and hence of after-pulsing and optical Cross-talk phenomenons, mainly due to an effective reduction of the carriers trapped as well as the photons produced during the avalanche. The direct cross-talk and the after-pulse probabilities measured at maximum efficiency are equal to 25% and 2% respectively, halved with respect to the standard NUV devices.
Primary author
Dr
Giovanni Paternoster
(Fondazione Bruno Kessler)
Co-authors
Dr
Alberto Gola
(Fondazione Bruno Kessler)
Mr
Alessandro Ferri
(Fondazione Bruno Kessler)
Dr
Claudio Piemonte
(Fondazione Bruno Kessler)
Dr
Fabio Acerbi
(Fondazione Bruno Kessler)
Mr
GAETANO ZAPPALA'
(UNIVERSITY OF TRENTO)
Dr
Nicola Zorzi
(Fondazione Bruno Kessler - FBK)
