title: Efficient emission facilitated by multiple energy level transitions in uniform graphitic carbon nitride films deposited by thermal vapor condensation.
abstract: Graphitic carbon nitride (g-CN) films are important components of optoelectronic devices, but current techniques for their production, such as drop casting and spin coating, fail to deliver uniform and pinhole-free g-CN films on solid substrates. Here, versatile, cost-effective, and large-area growth of uniform and pinhole-free g-CN films is achieved by using a thermal vapor condensation method under atmospheric pressure. A comparison of the X-ray diffraction and Fourier transform infrared data with the calculated infrared spectrum confirmed the graphitic build-up of films composed of tri-s-triazine units. These g-CN films possess multiple active energy states including π*, π, and lone-pair states, which facilitate their efficient (6% quantum yield in the solid state) photoluminescence, as confirmed by both experimental measurements and theoretical calculations.
authors.affiliation: Department of Physics and Materials Science and Centre for Functional Photonics (CFP), City University of Hong Kong, No 83, Tat Chee Avenue, Hong Kong S.A.R. (China).
authors.forename: Juncao
authors.initials: J
authors.lastname: Bian
authors.forename: Jianfu
authors.initials: J
authors.lastname: Li
authors.forename: Sergii
authors.initials: S
authors.lastname: Kalytchuk
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.forename: Tsz Chun
authors.initials: TC
authors.lastname: Lau
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Niehaus
authors.forename: Andrey L
authors.initials: AL
authors.lastname: Rogach
authors.forename: Rui-Qin
authors.initials: RQ
authors.lastname: Zhang
keywords: energy levels; graphitic carbon nitride; luminescence; thermal vapor condensation; thin films