High-field spatial imaging of charge transport in silicon at low temperature

• Published in: AIP advances Vol. 10; no. 2
• Main Authors: Stanford, C., Moffatt, R. A., Kurinsky, N. A., Brink, P. L., Cabrera, B., Cherry, M., Insulla, F., Kelsey, M., Ponce, F., Sundqvist, K., Yellin, S., Young, B. A.
• Format: Journal Article
• Language: English
• Published: United States American Institute of Physics (AIP) 11.02.2020
• Subjects: PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
• ISSN: 2158-3226; 2158-3226

We present direct imaging measurements of charge transport across a 1 cm x 1 cm x 4 mm-thick crystal of high purity silicon ($\sim$15 k$\Omega$-cm) at temperatures of 5 K and 500 mK. We use these data to measure the lateral diffusion of electrons and holes as a function of the electric field applied along the [111] crystal axis, and to verify our low-temperature Monte Carlo software. The range of field strengths in this paper exceed those used in the previous study (DOI: 10.1063/1.5049691) by a factor of 10, and now encompasses the region in which some recent silicon dark matter detectors operate (DOI: 10.1103/PhysRevLett.121.051301). We also report on a phenomenon of surface charge trapping which can reduce expected charge collection.