Speaker
Prof.
Robert Klanner
(University of Hamburg)
Description
The breakdown behaviour of prototype SiPMs (Silicon Photomultiplier) with pixel sizes of 15×15, 25×25 and 50×50 μm^2 manufactured by KETEK has been investigated. The I-V (current-voltage) characteristics and the PA (pulse-area) spectra have been measured as a function of bias voltage in dark conditions, as well as with the SiPM illuminated with an LED with a wavelength of 470 nm. The measurements were made in the temperature range between –20 °C and +20 °C. From the PA spectra the gain, G(V), and from a linear fit to G(V), the gain-breakdown voltage, V_bd^G, have been obtained. From fits to the I-V curves with and without LED illumination below and above breakdown, the current-breakdown voltage, V_bd^I, has been determined. It is found that there is a significant difference between V_bd^G and V_bd^I. The difference V_bd^I-V_bd^G is positive and increases with decreasing pixel size. We explain this difference by the difference between the turn-on and the turn-off voltage of the Geiger discharge. A possible model of the V_bd^I-V_bd^G difference is presented.
Primary author
Prof.
Robert Klanner
(University of Hamburg)
Co-authors
Prof.
Erika Garutti
(University of Hamburg)
Dr
Joern Schwandt
(University of Hamburg)
Mr
Michael Nitschke
(University of Hamburg)
Dr
Valery Chmill
(University of Hamburg)
