Direct detection sensors are forseen as successors to scintillation based technology in future ionizing radiation imaging. Research activity has shown CdZnTe to be the best suited sensor material for many new detector applications. Its greatest potential is in emission imaging to serve as a compact, high spatial resolution gamma camera, and radiography will benefit through single photon transmission imaging. Commercial viability is a major obstacle to any new system based on CdZnTe due its low yields and high costs. An alternative production technique is proposed to alleviate this problem. Horizontal Bridgman growth of CdZnTe will be demonstrated, modified and assessed. Resulting materials will undergo physical and electrical testing, conducted both by RMD and collaborators at Sandia National Lab. Phase I will focus on growth of small 50 g ingots with compensational doping. The first goal is to achieve high device quality, the second step (extending to Phase II) will be scaling the procedure to yield the large, uniform substrates needed for imaging.
The CdZnTe material produced by this project will allow several new imaging detectors to become economically feasable. Devices will include general purpose and organ specific gamma cameras, new radiographic linear scanners and replacement detectors for conventional computed tomography.
