Measurement of Quantum Yields of Monolayer TMDs Using Dye-Dispersed PMMA Thin Films
Open Access
- 27 May 2020
- journal article
- research article
- Published by MDPI AG in Nanomaterials
- Vol. 10 (6), 1032
- https://doi.org/10.3390/nano10061032
Abstract
In general, the quantum yields (QYs) of monolayer transition metal dichalcogenides (1L-TMDs) are low, typically less than 1% in their pristine state, significantly limiting their photonic applications. Many methods have been reported to increase the QYs of 1L-TMDs; however, the technical difficulties involved in the reliable estimation of these QYs have prevented the general assessment of these methods. Herein, we demonstrate the estimation of the QYs of 1L-TMDs using a poly methyl methacrylate (PMMA) thin film embedded with rhodamine 6G (R6G) as a reference specimen for measuring the QYs of 1L-TMDs. The PMMA/R6G composite films with thicknesses of 80 and 300 nm demonstrated spatially homogeneous emissions with the incorporation of well-dispersed R6G molecules, and may, therefore, be used as ideal reference specimens for the QY measurement of 1L-TMDs. Using our reference specimens, for which the QY ranged from 5.4% to 22.2% depending on the film thickness and R6G concentrations, we measured the QYs of the exfoliated or chemical vapor deposition (CVD)-grown 1L-WS2, -MoSe2, -MoS2, and -WSe2 TMDs. The convenient procedure proposed in this study for preparing the thin reference films and the simple protocol for the QY estimation of 1L-TMDs may enable accurate comparisons of the absolute QYs between the 1L-TMD samples, thereby enabling the development of a method to improve the QY of 1L-TMDs.Keywords
Funding Information
- National Research Foundation of Korea (NRF-2019R1I1A1A01062630, NRF-2018R1C1B6008176)
This publication has 47 references indexed in Scilit:
- Self-Driven Photodetector and Ambipolar Transistor in Atomically Thin GaTe-MoS2 p–n vdW HeterostructureACS Applied Materials & Interfaces, 2016
- Monolayer excitonic laserNature Photonics, 2015
- Exciton dynamics and annihilation in WS2 2D semiconductorsNanoscale, 2015
- Ultrafast Dynamics of Defect-Assisted Electron–Hole Recombination in Monolayer MoS2Nano Letters, 2014
- Ultrasensitive photodetectors based on monolayer MoS2Nature Nanotechnology, 2013
- Intrinsic Structural Defects in Monolayer Molybdenum DisulfideNano Letters, 2013
- Electroluminescence in Single Layer MoS2Nano Letters, 2013
- Electronics and optoelectronics of two-dimensional transition metal dichalcogenidesNature Nanotechnology, 2012
- Atomically Thin: A New Direct-Gap SemiconductorPhysical Review Letters, 2010
- Emerging Photoluminescence in Monolayer MoS2Nano Letters, 2010