Dr. Ge Yang
Department of Nuclear Engineering
North Carolina State University

Abstract

Compound semiconductor radiation detectors, e,g, CdZnTe, have attracted a sustained research interest due to their great potential for room-temperature X-ray and gamma-ray detection. These detectors are able to deliver excellent energy-resolution and high detection-efficiency while operating at room temperature. The above merits enable the deployment of CdZnTe detectors in a wide range of applications including nonproliferation inspections, nuclear-medical imaging, industrial process monitoring, astronomical phenomenon observations, environmental safety and remediation, and basic physics investigations. Central to the movement of compound semiconductor nuclear detector technologies have been the development of detector materials and advanced detector designs. In this seminar I will focus on several important factors that substantially affect the performance of CdZnTe detectors and discuss the corresponding solutions to address these challenges.

I will present and analyze the test data from high-spatial-resolution detector response mapping, internal electric field measurements, white beam X-ray diffraction topography, infrared (IR) microscopy, low-temperature photoluminescence spectroscopy, and current-voltage measurements and examine their correlation with the integrated device performance. Furthermore the post-growth annealing approach will be introduced, which is a promising method to reduce the effects of material defects and could largely improve the performance of detector materials. At the end of the talk, I will offer my opinions in terms of the development of several emerging radiation detector materials and devices.