Strong photoluminescence enhancement of MoS(2) through defect engineering and oxygen bonding.

By H. Nan, Zilu Wang, Wenhui Wang, Zheng Liang, Yan Lu, Qian Chen, Daowei He, P. Tan, Feng Miao, Xinran Wang and 2 more. ACS Nano, 2014

1,125 citations recorded by the source corpus.

We report on a strong photoluminescence (PL) enhancement of monolayer MoS2 through defect engineering and oxygen bonding. Micro-PL and Raman images clearly reveal that the PL enhancement occurs at cracks/defects formed during high-temperature annealing. The PL enhancement at crack/defect sites could be as high as thousands of times after considering the laser spot size. The main reasons of such huge PL enhancement include the following: (1) the oxygen chemical adsorption induced heavy p doping and the conversion from trion to exciton; (2) the suppression of nonradiative recombination of excitons at defect sites, which was verified by low-temperature PL measurements. First-principle calculations reveal a strong binding energy of ∼2.395 eV for an oxygen molecule adsorbed on a S vacancy of MoS2. The chemically adsorbed oxygen also provides a much more effective charge transfer (0.997 electrons per O2) compared to physically adsorbed oxygen on an ideal MoS2 surface. We also demonstrate that the defect engineering and oxygen bonding could be easily realized by mild oxygen plasma irradiation. X-ray photoelectron spectroscopy further confirms the formation of Mo-O bonding. Our results provide a new route for modulating the optical properties of two-dimensional semiconductors. The strong and stable PL from defects sites of MoS2 may have promising applications in optoelectronic devices.

Subfields: Electrical and Electronic Engineering, Materials Chemistry, Molecular Biology

View Paper: https://www.semanticscholar.org/paper/3ccec212289a19c1f3d5f66e7fc8b4d86cf1184d

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Electrical and Electronic Engineering

1. Zhenhua Ni
2. Zhangting Wu
3. S. Khondaker

In Materials Chemistry

1. Zhangting Wu
2. Zhenhua Ni
3. Xinran Wang
4. H. Nan
5. S. Khondaker
6. Litao Sun

Citations in the corpus

• Photoluminescence Quenching in Single-layer MoS2 via Oxygen Plasma Treatment (2014, background): “13 Although significant efforts have been placed in understanding the properties and applications of pristine SL MoS2,(9-22) altering the properties of SL MoS2 via creating and manipulating defects through external control is still in its infancy.(23-29) Such defect engineering can modify the optica”
• Defects as a factor limiting carrier mobility in WSe2: A spectroscopic investigation (2016, methodology): “Furthermore, by manipulating the focused laser beam, such optical methods can have spatial resolution varying from sub-micrometer to centimeter [20, 21].”