title: A novel and functional single-layer sheet of ZnSe.
abstract: The recently synthesized freestanding four-atom-thick double-layer sheet of ZnSe holds great promise as an ultraflexible and transparent photoelectrode material for solar water splitting. In this work, we report theoretical studies on a novel three-atom-thick single-layer sheet of ZnSe that demonstrates a strong quantum confinement effect by exhibiting a large enhancement of the band gap (2.0 eV) relative to the zinc blende (ZB) bulk phase. Theoretical optical absorbance shows that the largest absorption of this ultrathin single-layer sheet of ZnSe occurs at a wavelength similar to its four-atom-thick double-layer counterpart, suggesting a comparable behavior on incident photon-to-current conversion efficiency for solar water splitting, among a wealth of potential applications. The results presented herein for ZnSe may be generalized to other group II-VI analogues.
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Bethel Valley Road, Oak Ridge, Tennessee 37831-6493, United States.
authors.forename: Jia
authors.initials: J
authors.lastname: Zhou
authors.forename: Bobby G
authors.initials: BG
authors.lastname: Sumpter
authors.forename: Paul R C
authors.initials: PR
authors.lastname: Kent
authors.forename: Jingsong
authors.initials: J
authors.lastname: Huang
keywords: BSE; DFT; GW approximation; Two-dimensional materials; photovoltaic