Scientific/Technical Report: Improvement in compensation and crystal growth of cadmium zinc telluride radiation detectors (open access)

Scientific/Technical Report: Improvement in compensation and crystal growth of cadmium zinc telluride radiation detectors

Comparison of actual accomplishments with goals and objectives: (1) Growth of 12 ingots--Washington State University (WSU) more than met this goal for the project by growing 12 final ingots for the year. Nine of the twelve crystal growth ingots resolved gamma radiation at room temperature. The other three ingots where resistivity of {approx} 3 x 10{sup 8} Ohm*cm for CG32a, CG36, and CG42 lower than expected, however none of these were tried with blocking contacts. All ingots were evaluated from tip to heel. In these three cases, the group III, dopant Aluminum (Al) was not detected to a level to compensate the Cd vacancies in the cadmium zinc telluride (CZT) thus the ingots were lower resistivity. The nine ingots that were successful radiation detectors averaged a bulk resistivity of 1.25 x 10{sup 10} Ohm*cm and with a average {mu}{tau} product for electrons of {approx} 2 x 10{sup -4} cm{sup 2}/V with a 1/4 microsecond shaping time with samples {approx}2 mm in thickness. (2) Attempt new compensations techniques--WSU also met this goal. Several doping schemes were attempted and investigated with various amounts of excess Tellurium added to the growth. The combination of Al and Erbium (Er) were first attempted for these …
Date: May 19, 2007
Creator: Lynn, Kelvin G. & Jones, Kelly A.
System: The UNT Digital Library