Development of InSb Low-Energy Threshold Detector for Dark Matter Searches

At the University of South Dakota, we have been successfully growing Ge single crystals for a decade by using the Czochralski method. These Ge detector-grade single crystals are fabricated into radiation detectors used in many research and application areas such as rare event physics. However, a new semiconductor is still necessary especially in high-resolution X-rays and gamma-rays spectroscopy with a low-energy threshold. The most promising binary semiconductor is Indium Antimonide (InSb), which can be developed as a future ultra-high-resolution radiation detector due to its very small bandgap of 0.165 eV and large electron mobility of 78000 cm²V^-1s^-1. This small bandgap could provide even better energy resolution and peak-to-Compton ratios than Ge does.

Most of the previous works on the InSb crystal were concentrated on infrared applications. In this work, we present theoretical calculations of InSb detectors compared to our own HPGe radiation detectors and present the experimental setup to grow the single crystal of InSb by the Czochralski method in our lab.

 

This work is supported by NSF OISE 1743790 and the PIRE-GEMADARC collaboration.