Date of Award
Doctor of Philosophy
Eric D. Lukosi
Jason P. Hayward, Charles L. Melcher, Mahshid Ahmadi
Metal halide perovskite (MHP) semiconductors have attracted significant interest in recent years within photovoltaic and radiation detection communities due to their inexpensive solution growths, high effective atomic number for gamma and X-ray sensing, suitable bandgap, large resistivity, and moderate mobility-lifetime products. The MHP stoichiometry can also be tuned as needed to achieve desired physical and electronic properties. Moreover, the hybrid or organometallic halide perovskite (OMHP) variants contain a large atomic fraction of hydrogen for fast neutron sensing. These qualities make MHPs an attractive low-cost option for meeting detector needs within nuclear security and imaging applications. This work presents the development of MHPs for radiation sensing, with the majority of the results pertaining to a specific OMHP variant, methylammonium lead tribromide (CH3NH3PbBr3, MAPbBr3, or MAPB). The implementation of birefringence screening, chemomechanical polishing, and tin oxide electrode designs as improvements to the detector fabrication process are demonstrated, followed by benchmarking of the charge transport properties through alpha particle irradiation, X-ray induced photocurrents, and deconvolution of preamplifier signals. Notable achievements in radiation sensing are then presented, including X-ray imaging with MAPB, the development of a bi-parametric program to improve gamma ray sensing, and thermal neutron sensing with lithium-doped MAPB. Finally, the negative effects of radiation damage on the performance of MHP devices are demonstrated, followed by the evaluation of annealing and low temperature testing as strategies to mitigate detector degradations over time and improve radiation detection performance. Although certain challenges remain to minimize physical and electronic defects to improve detector stability and charge transport properties, the methods and findings presented in this thesis demonstrate the potential for MHP radiation sensors to meet detector requirements within nuclear security and imaging applications.
Tan, Ryan, "Development of Metal Halide Perovskites for Radiation Detection. " PhD diss., University of Tennessee, 2022.