Evaluating the Radiation Effects on the Characteristics of the Silicon Avalanche Photodiode with Protons

Abstract

Silicon avalanche photodiode (Si APD) plays important roles in high sensitive optical detecting applications, such as remote sensing, radiation detection and optical communication etc. However, in the space, the Si APD would unavoidably suffer radiation damage, which would degrade the Si APD performance, like dark current, responsivity and gain etc. Here, we report the results of Si APD radiation tests with protons to evaluate their radiation hardness properties and suitability for space missions. With this motivation, samples have been radiated using 50 MeV protons with maximum does 1E12 p(proton)/cm2 The test results show that the Si APD dark current increment is negligible when the radiation dose is below 1E11 p/cm2, ∼10 nA, satisfying most nanowatt level detecting applications. As the radiation dose further increases to 1E12 p/cm2, the Si APD breakdown voltage has a measureable decrement, which subsequently increases the dark current and gain. And through over two years’ in-orbit test, the Si APD dark current keeps below 1 nA, while the responsively is ∼4.9 A/W.