Radiation hardness of amorphous silicon particle sensors

Radiation tests of 32 $\mu \mathrm{m}$ thick hydrogenated amorphous silicon n–i–p diodes have been performed using a high-energy 24 GeV proton beam up to fluences of $2 \times 10^{16}$ protons/cm$^2$. The results are compared to irradiation of similar 1 $\mu \mathrm{m}$ and 32 $\mu \mathrm{m}$ thick n–i–p diodes using a proton beam of 405 keV at a fluence of $3 \times 10^{13}$ protons/cm$^2$. All samples exhibited a drop of the photoconductivity and an increase in the dark leakage current under both high- and low-energy proton irradiation. An almost full recovery of the device performance was observed after a subsequent thermal annealing.