We develop a framework powered by machine learning (ML) and high-throughput density functional theory (DFT) computations for the prediction and screening of functional impurities in groups IV, III-V, and II-VI zinc blende semiconductors. Elements spanning the length and breadth of the periodic table are considered as impurity atoms at the cation, anion, or interstitial sites in supercells of 34 candidate semiconductors, leading to a chemical space of approximately 12,000 points, 10% of which are used to generate a DFT dataset of charge dependent defect formation energies. Descriptors based on tabulated elemental properties, defect coordination environment, and relevant semiconductor properties are used to train ML regression models for the DFT computed neutral state formation energies and charge transition levels of impurities.
View Article and Find Full Text PDFThis tutorial review presents our perspective on designing organic molecules for the functionalization of inorganic nanomaterial surfaces, through the model of an "anchor-functionality" paradigm. This "anchor-functionality" paradigm is a streamlined design strategy developed from a comprehensive range of materials (, lead halide perovskites, II-VI semiconductors, III-V semiconductors, metal oxides, diamonds, carbon dots, silicon, ) and applications (, light-emitting diodes, photovoltaics, lasers, photonic cavities, photocatalysis, fluorescence imaging, photo dynamic therapy, drug delivery, ). The structure of this organic interface modifier comprises two key components: anchor groups binding to inorganic surfaces and functional groups that optimize their performance in specific applications.
View Article and Find Full Text PDFCarrier spins in semiconductor nanocrystals are promising candidates for quantum information processing. Using a combination of time-resolved Faraday rotation and photoluminescence spectroscopies, we demonstrate optical spin polarization and coherent spin precession in colloidal CsPbBr nanocrystals that persists up to room temperature. By suppressing the influence of inhomogeneous hyperfine fields with a small applied magnetic field, we demonstrate inhomogeneous hole transverse spin-dephasing times () that approach the nanocrystal photoluminescence lifetime, such that nearly all emitted photons derive from coherent hole spins.
View Article and Find Full Text PDFA number of recent studies have shown that older adults are more susceptible to context-based misperceptions in hearing (Rogers, Jacoby, & Sommers, Psychology and Aging, 27, 33-45, 2012; Sommers, Morton, & Rogers, Remembering: Attributions, Processes, and Control in Human Memory [Essays in Honor of Larry Jacoby], pp. 269-284, 2015) than are young adults. One explanation for these age-related increases in what we term false hearing is that older adults are less able than young individuals to inhibit a prepotent response favored by context.
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