title: Broadband Enhancement of Spontaneous Emission in Two-Dimensional Semiconductors Using Photonic Hypercrystals.
abstract: The low quantum yield observed in two-dimensional semiconductors of transition metal dichalcogenides (TMDs) has motivated the quest for approaches that can enhance the light emission from these systems. Here, we demonstrate broadband enhancement of spontaneous emission and increase in Raman signature from archetype two-dimensional semiconductors: molybdenum disulfide (MoS2) and tungsten disulfide (WS2) by placing the monolayers in the near field of a photonic hypercrystal having hyperbolic dispersion. Hypercrystals are characterized by a large broadband photonic density of states due to hyperbolic dispersion while having enhanced light in/out coupling by a subwavelength photonic crystal lattice. This dual advantage is exploited here to enhance the light emission from the 2D TMDs and can be utilized for developing light emitters and solar cells using two-dimensional semiconductors.
authors.forename: Tal
authors.initials: T
authors.lastname: Galfsky
authors.forename: Zheng
authors.initials: Z
authors.lastname: Sun
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Considine
authors.affiliation: Department of Material Science, National Tsing-Hua University , Hsinchu 20013, Taiwan.
authors.forename: Cheng-Tse
authors.initials: CT
authors.lastname: Chou
authors.affiliation: Department of Material Science, National Tsing-Hua University , Hsinchu 20013, Taiwan.
authors.forename: Wei-Chun
authors.initials: WC
authors.lastname: Ko
authors.affiliation: Department of Material Science, National Tsing-Hua University , Hsinchu 20013, Taiwan.
authors.forename: Yi-Hsien
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Birck Nanotechnology Center, School of Computer and Electrical Engineering, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Evgenii E
authors.initials: EE
authors.lastname: Narimanov
authors.forename: Vinod M
authors.initials: VM
authors.lastname: Menon
keywords: 2D materials; Hyperbolic metamaterials; photonic hyper crystal; plasmonics; purcell enhancement; transition metal dichalcogenides