$$\hbox {H}^{-}$$ H - -Like Centers and Space-Charge Effects in Cryogenic Germanium Detectors for Dark Matter Search

Abstract

Space-charge build-up phenomena are investigated in germanium detectors for dark matter search, associated with the thermal emission of carriers by the H\(^{-}\)-like, dopant-related A\(^{+ }\)and D\(^{-}\) shallow trap centers. Evidence for such processes follows from a combined study of the time evolution of the pattern of charge sharing between the different collection electrodes of the device, and of the kinetics of carrier emission by the A\(^{+ }\)and D\(^{- }\)centers. Implications for detector physics are discussed.