Radiation-Resistant High-Resolution Particle Sensors from Composites of Semiconductor Nanoparticles and Aramid Nanofibers

This SBIR Phase II project will demonstrate that high radiation-resistance can be elicited from nanostructured media composed of semiconducting nanoparticles derived from size-governed wide band-gap PbTe. In order to transform space-based particle sensors, nanocrystalline semiconductors provide an attractive material basis because they present a means of: 1) decreasing the underlying material cost by utilizing a solution-based fabrication methodology, 2) increasing the range of candidate materials by including the narrow-gap semiconductors, 3) increasing the exciton multiplicity upon the impingement of radiation by utilizing multi-exciton generation, and 4) increasing the radiation resistance because the introduction of a high density of nanoparticles can convey pronounced improvement in the radiation hardness of the material. During Phase I, we demonstrated various facile fabrication approaches to making nanostructured solids through which excited charge carriers can transport. Furthermore, one can exploit the accumulated effect of interfacial scattering events at the multitudinous boundaries with the nanostructured solid to enhance the stopping power of the solid relative to a homogeneous or single-crystalline equivalent. The research is designed to not only deliver a high-performance radiation resistant sensor that can be commercialized but it will also advance basic physics by studying the interactions between energetic particles and strongly-confined charge carriers. By finding general material-design methods to suppress both radiation-induced damage and the stochastic thermal loss component in semiconductor materials, one can greatly increase the charge-conversion efficiency, which impacts the resolution of sensing devices, such as the particle detection application targeted.