Collaborative Research: Correlating Optoelectronic Properties with Defects in One-Dimensional Perovskite Nanocrystals

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Recent research has witnessed rapid advances in metal halide perovskite materials for applications in solar cells, light-emitting diodes, photodetectors, lasers, and scintillators for spectroscopic gamma-ray detection and/or X-ray imaging due to their superior optoelectronic properties. Defects in perovskites can limit the transport of charge carriers and change the carrier concentrations. The ability to understand and recognize defects in perovskites is the key to control the performance in perovskite-based devices. This collaborative research aims to relate optoelectronic properties with defects in one-dimensional perovskite nanocrystals. These nanocrystals can be exploited either individually or as building blocks in the assembly of nanostructured materials and devices. These devices would be used in energy and biomedical applications, including optoelectronics, photonics, sensors, catalysis, nanotechnology, and biotechnology, among other emerging areas. As such, it transitions fundamental scientific discoveries into useful technologies that benefit society. This project offers opportunities for underrepresented female and minority undergraduate students as well as high school teachers and students to participate in nanomaterials research at both Georgia Tech and California State University-Bakersfield. In one-dimensional (1D) metal halide perovskites, defects, if present, are expected to exert a pronounced influence on the carrier transport behaviors and thus the electronic and optoelectronic properties. It is therefore of crucial importance to identify, understand, control, and possibly utilize defects in perovskite crystals. This collaborative research between Georgia Tech and California State University-Bakersfield seeks to craft 1D perovskite nanocrystals with precisely controlled dimensions, scrutinize their dimension-dependent optical properties, and correlate the resulting optoelectronic properties of these perovskite nanocrystals with defects via directly imaging defects and local transport barriers under optical excitations by capitalizing on a contactless dielectric force microscopy technique. The systematic investigation into the optical properties and defect characteristics of these monodisperse 1D perovskite nanocrystals enables the development of high-quality perovskite nanomaterials with desired optoelectronic properties and minimal deleterious defects, thereby rendering their use in a gamut of optoelectronic devices with improved performance.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.