All inorganic perovskite materials for low-cost, high performance X-ray imagers

The rising prevalence of cancer, increasing safety awareness among people working in radiation-prone environment, growing safety concerns after nuclear power plant disasters, spur in the number of PET/CT scans, increasing adoption of nuclear medicine and radiation therapy for diagnosis and treatment of various diseases, and potential terrorist attacks using radioactive and biological weapons are some of the elements driving the growing interest in the science and technology of radiation detection, monitoring and safety. The need for highly efficient X-ray radiation imaging and monitoring equipment in healthcare applications account for the largest social, economic, and technical impacts of this proposal. In this proposal, we plan to use a combination of proprietary perovskite synthesis with our expertise in device fabrication and access to unique TFT back plane electronics to develop a scalable low-cost X-ray imager using all inorganic perovskite devices able to absorb X-rays in the 10-100 keV range, pixel size below 100 micrometers and detection sensitivity >500 µC Gyair-1cm-2. The perovskite deposition process demonstrated includes simple, cost effective, and easy-to-scale mechano-chemical synthesis that yields high quality perovskite materials with tunable compositions which are used as the source material for the film deposition on large area substrates using either doctor blade, air brushing and/or closed-space sublimation. The proposed film deposition approach is compatible with low-cost synthesis and deposition methods that are scalable to large area without compromising performance. For Phase I our team will focus on identifying the integration approaches and fundamental materials properties (composition, bonding, defects, structure, doping, etc.) defining response to X-ray energies between 10-100KeV in perovskite systems with formula CsPbX3 and CsPb2X5 [where X = chlorine (Cl), bromine (Br), iodine (I) or a combination of any of these elements] to enable high efficiency, low-cost, X-ray detection systems. Unlike other inorganic materials used for X-ray detection, the proposed perovskite materials are solution processable at relatively low temperatures and we have calculated the cost for the system proposed to be in the order of US$1-3 /cm3. The growth of X-ray medical imaging market is primarily driven by the increasing demand for early disease diagnosis, rapidly growing geriatric population and the subsequent increase in the prevalence of associated diseases. Based on product type, CT scanners segment held the largest share of the global diagnostic imaging market, closely followed by X-ray imaging systems. Opportunities in the Homeland Security and Defense areas is expected to grow owing to the increased spending on internal security and military expenditure. Better imaging systems are also required at high value targets (ports of entry, airports, government building, train stations, etc.). Integration of inexpensive imaging x-ray systems will also enable its use in urban detection networks that require the development of reliable, large area detectors to enable interconnected networks to accurately detect potential threats.