Hard X-ray Imager Large Area Based on Perovskite Nanocrystal Materials

The current X-ray imaging devices ion the market cannot meet the rising requirements for more safe, higher resolution and portable X-ray imaging applications. These mainly indirect types use a combination of scintillators with photodetector arrays.  The only direct-type X-ray detectors are based on amorphous selenium (a-Se).  Although they have the best sharpness in imaging, they are not stable at elevated temperatures and not sensitive to hard X-ray.  Perotech is revolutionizing X-ray detection technology using metal halide perovskite nanocrystals for direct X-ray detection imagers. Metal halide perovskites are a new generation of semiconductor materials that has been intensively studied recently for efficient and low-cost solar cells. These new materials have 100,000 times larger mobility-lifetime product which is a figure-of-merit that determines semiconductor device sensitivity than a-Se. These materials have an exciting combination of properties including very good X-ray detection sensitivity, low cost, and ease of deposition onto large area X-ray detector flat panel using the solution process. Perotech in collaboration with University of North Carolina at Chapel Hill propose a novel perovskite material structure and integration methods with readout electronics to develop large area perovskite detectors. The project leverages our extensive experience in perovskite material development and understanding of requirements of integration. The success of this project will enable at least 1000 times higher detection sensitivity than amorphous selenium (a-Se) direct detectors and much higher resolution images than indirect detectors based on scintillators, while it will allow high spectrum resolution of <2% to both soft and hard X-ray. The proposed materials can be easily scaled up to an area as large as 30 cm×30 cm.