Lead-free bismuth-based semiconductor radiation detector

One of the major goals of the Defense Nuclear Nonproliferation Research and Development (DNN R&D) is to develop new devices for radiation detection. The objective is to detect and identify illicit nuclear materials using radiation detection materials capable of high energy resolution with high detection efficiency. Therefore, low-cost new semiconductor materials for room temperature radiation detector development are needed.We propose to develop two novel classes of semiconductor materials for room temperature gamma ray spectroscopy. Single crystal growth of these materials will be optimized, radiation detectors using these semiconductors will be fabricated, and their performance evaluated and compared with current state-of-the-art detectors.The overall goal of the Phase I effort is to demonstrate the feasibility of developing high-performance, low-cost semiconductor detector materials suitable for gamma-ray spectroscopy. The major focus of the Phase I effort will be on purification of starting materials using zone refining, crystal growth using optimized growth parameters, gamma-ray detector fabrication and its characterization. Different device structures will be investigated to obtain best detector performance.The goal of this project is to produce a very low-cost all-inorganic detector based on new classes of semiconductors, capable of gamma-ray detection as an alternative to current state-of-the-art materials. The radiation detection device is expected to have high resolution, high detection efficiency, low dark current, high yield, and low cost. The lower production cost will provide an opportunity to build low-cost, high-performance radiation instruments for special nuclear material control and accountability applications. Benefited research disciplines include laboratory fluorescence analysis (e.g., EDAX) and industrial elemental analysis (environmental tools, lead paint determination, RoHS compliance). There are also applications in homeland security (such as spectroscopic dosimeters and radioisotope identifiers) and in nuclear medicine (e.g., PET) where high performance spectrometers will have valuable performance improvements.