title: Design principles for shift current photovoltaics.
abstract: While the basic principles of conventional solar cells are well understood, little attention has gone towards maximizing the efficiency of photovoltaic devices based on shift currents. By analysing effective models, here we outline simple design principles for the optimization of shift currents for frequencies near the band gap. Our method allows us to express the band edge shift current in terms of a few model parameters and to show it depends explicitly on wavefunctions in addition to standard band structure. We use our approach to identify two classes of shift current photovoltaics, ferroelectric polymer films and single-layer orthorhombic monochalcogenides such as GeS, which display the largest band edge responsivities reported so far. Moreover, exploring the parameter space of the tight-binding models that describe them we find photoresponsivities that can exceed 100 mA W-1. Our results illustrate the great potential of shift current photovoltaics to compete with conventional solar cells.
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.|Department of Physics, University of Toronto, Ontario, Canada, M5S 1A7.
authors.forename: Ashley M
authors.initials: AM
authors.lastname: Cook
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: M Fregoso
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: Fernando
authors.initials: F
authors.lastname: de Juan
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: Sinisa
authors.initials: S
authors.lastname: Coh
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.|Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Joel E
authors.initials: JE
authors.lastname: Moore