# Analysis methods for highly radiation-damaged SiPMs

## TL;DR

This study evaluates various analysis techniques on highly neutron-irradiated SiPMs, examining electrical parameters and light response to understand damage effects across different fluences and temperatures.

## Contribution

It introduces and compares multiple analysis methods to characterize electrical and optical behavior of heavily radiation-damaged SiPMs.

## Key findings

- Breakdown voltage increases with neutron fluence.
- Dark-count rate rises significantly after irradiation.
- Response to light pulses degrades at high fluences.

## Abstract

Prototype SiPMs with 4384 pixels of dimensions $15 \times 15~\mu $m$^2$ produced by KETEK have been irradiated with reactor neutrons to eight fluences between $10^9$ and $5\times 10^{14}$ cm$^{-2}$. For temperatures between $-30~^\circ $C and $+30~^\circ $C capacitance-voltage, admittance-frequency, current-forward voltage, current-reverse voltage and charge-voltage measurements with and without illumination by a sub-nanosecond laser have been performed. The data have been analysed using different methods in order to extract the dependence on neutron fluence and temperature of the electrical parameters, the breakdown oltage, the activation energy for the current generation, the dark-count rate and the response to light pulses. The results from the different analysis methods are compared.