Accelerated Development of Next Generation Semiconductor Radiation Detectors

High energy resolution is a key performance metric of radiation detectors which determines the accuracy and speed of radioactive nuclide identification. CdZnTe (CZT) radiation detectors are currently the only commercially available room temperature semiconductor detectors, with their superior spectral resolution approaching performance of cooled High Purity Germanium detectors. The persistently high price and the very slow increase in the size of these detectors have limited the deployment of radiation detection instruments based on this detector. Under this program, we will develop technology for crystal growth and fabrication of gamma radiation detectors based on an emerging class of new materials, the perovskites. Perovskite detectors have already shown very high and promising energy resolution rapidly approaching that of CZT detectors. Perovskite crystals, however, offer the potential of significantly lower production cost and higher yield of superior detector materials. The Phase I goal of this program will be to establish the viability of two processes for melt growth of perovskite halide semiconductors to produce large-volume high-quality radiation detector materials at high yield; grow perovskite crystals by the solution method and conduct a detailed material and device characterization study of the solution- and melt-grown crystals to identify characteristics that would result in high energy resolution in solution-grown crystals which can be produced at very low cost. The high-resolution radiation detectors to be developed in this program have application in homeland security, nuclear stockpile monitoring, nuclear contamination monitoring, and nuclear plant monitoring. There is also increasing demand from the military to equip military vehicles with these types of detectors. In the medical imaging area, there is a rising demand for high resolution detectors for SPECT, bone mineral densitometry, surgical probes and multi-color photon counting computed tomography.