The capability of rapid detection and identification of nuclear isotopes is urgently needed to protect our nation from nuclear terrorism. A research team from the City College of New York, Optical Semiconductors, Inc. and Brookhaven National Laboratories will combine efforts in spectroscopic characterization, material growth, and device manufacturing/testing to improve CdMgTe as the material of choice for room temperature gamma-ray detectors. CdTe-based detectors have the potential of high efficiency and high spectral resolution at room temperature. Ge or Si detectors need cryogenic temperatures for operation and their stopping power is low. Mercury iodide detectors have high stopping power, but have many mechanical, and growth problems. Cadmium zinc telluride (CZT) has recently become prominent, but it has low yield and slow growth rate. Cadmium magnedium telluride (CMT) has many advantages in comparison: (i) it has a much smaller lattice mismatch for alloying and therefore better mechanical properties; (ii) it has higher bandgap and hence high resistivity at ambient temperature; (iii) it should lead to easier fabrication of p-i-n device structure.
