Dopability on Complex Diamond-Like Semiconductors: new candidates for thermoelectric applications.
ORAL
Abstract
The diamond-like semiconductors (DLS) have recently garnered interest for the potential use as thermoelectric materials. DLS share the diamond structure, forming a chemically rich family of binary, ternary and quaternary compounds. To be a good thermoelectric, however, a material must be sufficiently dopable and the defect chemistry of this group is currently not well characterized.
In this work, we show our recent efforts to investigate the defect physics of these complex materials using first-principles calculations. We focus on a subset within the DLS, formed by ternary and quaternary tellurides. We show that there is a large diversity in the stability phase diagrams in this group and how this impact defect formation energies and the range of achievable carrier concentrations. Most of the ternaries show dopability windows ranging from highly p-type to intrinsic or slightly n-type. In addition, a control of carrier concentrations can be achieved by growth under different thermodynamic environments. We also highlight the importance of the computational approach to an accurate prediction of these quantities, that can be used to guide experimental works.
In this work, we show our recent efforts to investigate the defect physics of these complex materials using first-principles calculations. We focus on a subset within the DLS, formed by ternary and quaternary tellurides. We show that there is a large diversity in the stability phase diagrams in this group and how this impact defect formation energies and the range of achievable carrier concentrations. Most of the ternaries show dopability windows ranging from highly p-type to intrinsic or slightly n-type. In addition, a control of carrier concentrations can be achieved by growth under different thermodynamic environments. We also highlight the importance of the computational approach to an accurate prediction of these quantities, that can be used to guide experimental works.
*We acknowledge the support of the National Center for Supercomputing Applications and the NSF via grants 1729594 and 1729149.
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Presenters
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Lidia Gomes
- Department of Physics and Centre for Advanced 2D Materials, National University of Singapore
- University of Illinois at Urbana-Champaign