Development of planar P-type point contact germanium detectors for low-mass dark matter searches

Journal Article · 07 March 2022 · European Physical Journal. C, Particles and Fields

DOI: https://doi.org/10.1140/epjc/s10052-022-10162-x · OSTI ID:1980802

Wei, W. -Z. ^[1]; Mei, H. ^[2]; Kooi, K. ^[2]; Mei, D. -M. ^[2]; Liu, J. ^[2]; Li, J. -C. ^[2]; Panth, R. ^[2]; Wang, G. -J. ^[2]

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1. Univ. of South Dakota, Vermillion, SD (United States); Univ. of South Dakota, Vermillion, SD (United States)
2. Univ. of South Dakota, Vermillion, SD (United States)

The detection of low-energy deposition in the range of sub-eV through ionization using germanium (Ge) with a bandgap of ~ 0.7 eV requires internal amplification of the charge signal. This can be achieved through high electric field that accelerates charge carriers, which can then generate more charge carriers. The minimum electric field required to generate internal charge amplification is derived for different temperatures. We report the development of a planar point contact Ge detector in terms of its fabrication and the measurements of its leakage current and capacitance as a function of applied bias voltage. With the determination of the measured depletion voltage, the field distribution is calculated using GeFiCa, which predicts that the required electric field for internal charge amplification can be achieved in proximity to the point contact. The energy response to an Am-241 source is characterized and discussed. We conclude that such a detector with internal charge amplification can be used to search for low-mass dark matter.

• Research Organization: Univ. of South Dakota, Vermillion, SD (United States)
• Sponsoring Organization: National Science Foundation (NSF); USDOE Office of Science (SC)
• Grant/Contract Number: SC0004768
• OSTI ID: 1980802
• Journal Information: European Physical Journal. C, Particles and Fields, Journal Name: European Physical Journal. C, Particles and Fields Journal Issue: 3 Vol. 82; ISSN 1434-6044
• Publisher: SpringerCopyright Statement
• Country of Publication: United States
• Language: English