Designing New Semiconductor Materials with Multinary Cu-Chalcogenide Nanocrystals

Transition metal multinary chalcogenides are a unique class of material for photovoltaic and quantum dot light emitting applications. They offer a higher level of flexibility from a materials perspective to achieve tunable band gaps through structural and compositional control. We aim to realize new and more sustainable direct band-gap semiconductor materials from multinary compositions of earth-abundant elements. To this end, detailed <i>ab initio</i> calculations are first performed for the parent binary Cu-chalcogenide composition. A series of new p-doped, n-doped, and degenerate semiconductors based on multinary Cu-chalcogenide nanocrystals are predicted using the theoretical investigations of the band gap and density of states. We experimentally realized the new multinary Cu-chalcogenide compositions via novel solution chemistry approaches. A detailed material characterization based on x-ray diffraction, electron microscopy, and ultraviolet-visible spectroscopy is reported for the new Cu-chalcogenide nanocrystals and thin films. These new results will provide key theoretical and experimental insights for achieving more sustainable absorber layer materials for inorganic solar cells and quantum dot light emitting devices.