Nanocomposite Quantum Dot and Perovskite Scintillators
Abstract
The emerging field of nanocomposite organic scintillators offers a new class of scintillating materials with unique physical and mechanical properties. These nano-scale materials exhibit exceptionally high light yields due to quantum confinement effects, and so have great potential for use as high performance and low cost scintillation-based radiation detectors. Through the use of simple and scalable fabrication techniques such as solvent-based processing and spray coating, nanocomposite scintillators offer a break-through in cost for next-generation radiation detectors. Despite these attractive properties, these materials are in their infancy and significant work is required to understand the fundamental physical processes that define their function, and to optimize their performance for radiation detection applications. In this program we propose to develop new nanocrystalline organic scintillators using two distinct material systems -semiconducting quantum dots and nanocrystalline metal halide perovskite nanocrystals. We will undertake a complete study of the physical and optical properties of these materials to characterize their light yield, quenching effects and dynamic time response. We will carry out fundamental measurements of their scintillation response to radiation, including X-ray response linearity, and spectroscopic performance using gamma-emitting radioisotopes. These materials exhibit an extremely fast response time with very little time-lag or afterglow. We will carry out time-resolved measurements to study scintillation dynamics as a function of temperature and material composition, in order to optimize these materials for high rate applications. Monte Carlo modelling of optical photon transport using Geant4 will be used to understand optical transport processes in nanocrystalline materials, and to minimize effects from internal optical scattering. In the extension activities during Years 4 and 5 of the project we will develop silicon photomultiplier (SiPM) readout for nanocrystalline organic scintillators, exploiting the high performance and small form factor of the latest low-noise SiPM sensors. Working with our industrial partner Kromek we will develop digital instrumentation and pulse processing algorithms using high speed waveform digitizers and embedded FPGA real-time algorithms. We will also develop neutron-sensitive variants of these organic scintillators through the addition of gadolinium nanoparticles into the scintillator matrix. The successful outcome of this research will significantly advance the fundamental understanding of optical performance and radiation response of organic nanocomposite scintillators and develop the required detector technology for high sensitivity, low cost scintillator.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 16, 2019
- Source ID
- HDTRA11810019
Entities
People
- Paul Sellin
Organizations
- Defense Threat Reduction Agency
- University of Surrey