Investigation of the electrical conduction mechanisms in P-type amorphous germanium electrical contacts for germanium detectors in searching for rare-event physics
- Univ. of South Dakota, Vermillion, SD (United States)
For the first time, electrical conduction mechanisms in the disordered material system is experimentally studied for p-type amorphous germanium (a-Ge) used for high-purity Ge detector contacts. The localization length and the hopping parameters in a-Ge are determined using the surface leakage current measured from three high-purity planar Ge detectors. The temperature dependent hopping distance and hopping energy are obtained for a-Ge fabricated as the electrical contact materials for high-purity Ge planar detectors. As a result, we find that the hopping energy in a-Ge increases as temperature increases while the hopping distance in a-Ge decreases as temperature increases. The localization length of a-Ge is on the order of 2.13$$^{-0.05}_{+0.07}$$A° to 5.07$$^{0.83}_{+2.58}$$A°,depending on the density of states near the Fermi energy level within bandgap. Using these parameters, we predict that the surface leakage current from a Ge detector with a-Ge contacts can be much smaller than one yocto amp (yA) at helium temperature, suitable for rare-event physics searches.
- Research Organization:
- Univ. of South Dakota, Vermillion, SD (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); National Science Foundation (NSF); University of South Dakota
- Grant/Contract Number:
- SC0004768; FG02-10ER46709; OISE1743790; PHYS 1902577; OIA 1738695
- OSTI ID:
- 1850848
- Journal Information:
- European Physical Journal. C, Particles and Fields, Vol. 80, Issue 10; ISSN 1434-6044
- Publisher:
- SpringerCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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