Abstract
Impressive properties arise from the atomically thin nature of transition metal dichalcogenide two-dimensional materials. However, being atomically thin limits their optical absorption or emission. Hence, enhancing their photoluminescence by plasmonic nanostructures is critical for integrating these materials in optoelectronic and photonic devices. Typical photoluminescence enhancement from transition metal dichalcogenides is 100-fold, with recent enhancement of 1,000-fold achieved by simultaneously enhancing absorption, emission and directionality of the system. By suspending WSe2 flakes onto sub-20-nm-wide trenches in gold substrate, we report a giant photoluminescence enhancement of ~20,000-fold. It is attributed to an enhanced absorption of the pump laser due to the lateral gap plasmons confined in the trenches and the enhanced Purcell factor by the plasmonic nanostructure. This work demonstrates the feasibility of giant photoluminescence enhancement in WSe2 with judiciously designed plasmonic nanostructures and paves a way towards the implementation of plasmon-enhanced transition metal dichalcogenide photodetectors, sensors and emitters.
Original language | English (US) |
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Journal | Nature Communications |
Volume | 7 |
Issue number | 1 |
DOIs | |
State | Published - May 6 2016 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: Z. W. acknowledges scholarship support from NUS Graduate School for Integrative Sciences & Engineering (NGS). Z. W. and A.T.S.W. acknowledge the funding support from MOE Tier 1 grant R 144-000-321-112 and facility support from NUS Center for Advanced 2D Materials. Z.D. and J.K.W.Y. acknowledge the funding support from the Agency for Science, Technology and Research (A*STAR) Young Investigatorship (grant number 0926030138), SERC (grant number 092154099), the National Research Foundation (grant number NRF-CRP 8-2011-07), and A*STAR-JCO under project number 1437C00135. C.-W.Q acknowledges the financial support from A*STAR Pharos Programme (Grant No. 152 70 00014, with Project No. R-263-000-B91-305). S.A.M. acknowledges the EPSRC Reactive Plasmonics Programme Grant (EP/M013812/1), the Royal Society, and the Lee-Lucas Chair in Physics. L.-J.L. acknowledges support from KAUST (Saudi Arabia) and Taiwan Consortium of Emergent Crystalline Materials (TCECM). G.E. acknowledges Singapore National Research Foundation, Prime Minister s Office, Singapore, for funding the research under its Medium-sized Centre program as well as NRF Research Fellowship (NRF-NRFF2011-02).