title: Direct Band Gap Gallium Antimony Phosphide (GaSbxP(1-x)) Alloys.
abstract: Here, we report direct band gap transition for Gallium Phosphide (GaP) when alloyed with just 1-2 at% antimony (Sb) utilizing both density functional theory based computations and experiments. First principles density functional theory calculations of GaSbxP(1-x) alloys in a 216 atom supercell configuration indicate that an indirect to direct band gap transition occurs at x = 0.0092 or higher Sb incorporation into GaSbxP(1-x). Furthermore, these calculations indicate band edge straddling of the hydrogen evolution and oxygen evolution reactions for compositions ranging from x = 0.0092 Sb up to at least x = 0.065 Sb making it a candidate for use in a Schottky type photoelectrochemical water splitting device. GaSbxP(1-x) nanowires were synthesized by reactive transport utilizing a microwave plasma discharge with average compositions ranging from x = 0.06 to x = 0.12 Sb and direct band gaps between 2.21 eV and 1.33 eV. Photoelectrochemical experiments show that the material is photoactive with p-type conductivity. This study brings attention to a relatively uninvestigated, tunable band gap semiconductor system with tremendous potential in many fields.
authors: Department of Chemical Engineering and Conn Center for Renewable Energy Research University of Louisville, Louisville, KY, USA.
authors: H B
authors: HB
authors: Russell
authors: Institute of Electronic Structure and Laser (IESL), Foundation of Research and Technology-Hellas (FORTH), Heraklion, Crete, Greece.
authors: A N
authors: AN
authors: Andriotis
authors: Center for Computational Sciences, University of Kentucky, Lexington, KY, USA.|Department of Physics and Astronomy, University of Kentucky, Lexington, KY, USA.
authors: M
authors: M
authors: Menon
authors: Department of Chemical Engineering and Conn Center for Renewable Energy Research University of Louisville, Louisville, KY, USA.
authors: J B
authors: JB
authors: Jasinski
authors: Department of Chemical Engineering and Conn Center for Renewable Energy Research University of Louisville, Louisville, KY, USA.
authors: A
authors: A
authors: Martinez-Garcia
authors: Department of Chemical Engineering and Conn Center for Renewable Energy Research University of Louisville, Louisville, KY, USA.
authors: M K
authors: MK
authors: Sunkara