title: Theoretically Manipulating Quantum Dots on Two-Dimensional TiO2Monolayer for Effective Visible Light Absorption.
abstract: Low solar energy harvesting and conversion efficiency has become a major problem in solar energy science and engineering owing to the difficulty in capturing solar energy across the wide solar spectrum, especially in the visible light range. Inspired by the extraordinary properties of materials arising from decreased dimensions, in this study, we explore a nanocontact system formed by a two-dimensional (2D) TiO2monolayer and II-VI semiconductor (CdX)13(X = S, Se, and Te) nanocages for engineering the visible light absorption. The nanocontact system, via either Ti-X or Cd-O bond coupling mechanism, forms an ideal type II band alignment, where the stronger donor-acceptor coupling in the Ti-X contact system more efficiently relaxes the coupled geometry and helps it to couple to more electrons, therefore leading to an enhancement of the absorption peaks in the visible frequency range. On changing the element X in (CdX)13from S to Se then Te, a red shift of the visible light absorption peaks accompanied by stimulating optical response of the whole nanocontact system was observed. Nanocontacting semiconductors comprising low-dimensional (CdX)13nanocage@TiO2monolayer systems, which promote charge separation and optical absorption in the visible range that arise from the effects of adsorbent nature, decreasing size, and efficient interfacial coupling mechanism, are therefore promising photovoltaic and photocatalytic materials.
authors.affiliation: Institute for Superconducting & Electronic Materials, University of Wollongong, Australia and ‡School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology , Brisbane, QLD 4000, Australia.
authors.forename: Ting
authors.identifier: http://orcid.org/0000-0001-7488-6244
authors.initials: T
authors.lastname: Liao
authors.affiliation: Institute for Superconducting & Electronic Materials, University of Wollongong, Australia and ‡School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology , Brisbane, QLD 4000, Australia.
authors.forename: Ziqi
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Institute for Superconducting & Electronic Materials, University of Wollongong, Australia and ‡School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology , Brisbane, QLD 4000, Australia.
authors.forename: Shi Xue
authors.initials: SX
authors.lastname: Dou
keywords: DFT calculations; hybrid materials; monolayers; quantum dots; solar cells