Evidence of cluster dipole states in germanium detectors operating at temperatures below 10 K

Abstract

By studying charge trapping in germanium (Ge) detectors operating at temperatures below 10 K, we demonstrate for the first time that the formation of cluster dipole states from residual impurities is responsible for charge trapping. Two planar detectors with different impurity levels and types are used in this study. When drifting the localized charge carriers created by $\alpha$ particles from the top surface across a detector under a lower bias voltage, significant charge trapping is observed when compared to operating at a higher bias voltage. The amount of charge trapping shows a strong dependence on the type of charge carriers. Electrons are trapped more than holes in a p-type detector while holes are trapped more than electrons in a n-type detector. When both electrons and holes are drifted simultaneously using the widespread charge carriers created by $\gamma$ rays inside the detector, the amount of charge trapping shows no dependence on the polarity of bias voltage.

arXiv comment6 pages and 5 figures

References in corpus (14)

• Direct Detection of Sub-GeV Dark Matter
• Latest Results from the Heidelberg-Moscow Double Beta Decay Experiment
• Search for Low-Mass WIMPs with SuperCDMS
• Results on neutrinoless double beta decay of 76Ge from GERDA Phase I
• Search for an Annual Modulation in a P-type Point Contact Germanium Dark Matter Detector
• Results from a Low-Energy Analysis of the CDMS II Germanium Data
• The Igex 76ge Neutrinoless Double-Beta Decay Experiment: Prospects for Next Generation Experiments
• Light Dark Matter Search with a High-Resolution Athermal Phonon Detector Operated Above Ground
• First results on low-mass WIMP from the CDEX-1 experiment at the China Jinping underground Laboratory
• Constraints on low-mass WIMPs from the EDELWEISS-III dark matter search
• Direct Detection of MeV-Scale Dark Matter Utilizing Germanium Internal Amplification for the Charge Created by the Ionization of Impurities
• Fabrication and Characterization of High-Purity Germanium Detectors with Amorphous Germanium Contacts
• Impact of Charge Trapping on the Energy Resolution of Ge Detectors for Rare-Event Physics Searches
• The Impact of the Charge Barrier Height on Germanium (Ge) Detectors with Amorphous-Ge Contacts for Light Dark Matter Searches

Cited by in corpus (2)

• Development of low-threshold detectors for low-mass dark matter searches with a p-type germanium detector operated at cryogenic temperature
• Observation of Time-Dependent Internal Charge Amplification in a Planar Germanium Detector at Cryogenic Temperature