Exciton tuning in monolayer WSe2 via substrate induced electron doping. / Pan, Yang; Rahaman, Mahfujur; He, Lu et al.
In: Nanoscale Advances, Vol. 4, No. 23, 22.11.2022, p. 5102-5108.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Exciton tuning in monolayer WSe2 via substrate induced electron doping
AU - Pan, Yang
AU - Rahaman, Mahfujur
AU - He, Lu
AU - Milekhin, Ilya
AU - Manoharan, Gopinath
AU - Aslam, Muhammad Awais
AU - Blaudeck, Thomas
AU - Willert, Andreas
AU - Matković, Aleksandar
AU - Madeira, Teresa I
AU - Zahn, Dietrich R T
N1 - Acknowledgements: The authors gratefully acknowledge fnancial support by the Deutsche Forschungsgemeinschaft (DFG, projects ZA 146/43-1 and ZA 146/47-1). M. A. A. and A. M. acknowledge financial support by the Austrian Science Fund (FWF) under the grant no. I4323-N36. We thank Manuel Monecke for helping with the UPS measurement. This journal is © The Royal Society of Chemistry.
PY - 2022/11/22
Y1 - 2022/11/22
N2 - We report large exciton tuning in WSe2 monolayers via substrate induced non-degenerate doping. We observe a redshift of ∼62 meV for the A exciton together with a 1-2 orders of magnitude photoluminescence (PL) quenching when the monolayer WSe2 is brought in contact with highly oriented pyrolytic graphite (HOPG) compared to dielectric substrates such as hBN and SiO2. As the evidence of doping from HOPG to WSe2, a drastic increase of the intensity ratio of trions to neutral excitons was observed. Using a systematic PL and Kelvin probe force microscopy (KPFM) investigation on WSe2/HOPG, WSe2/hBN, and WSe2/graphene, we conclude that this unique excitonic behavior is induced by electron doping from the substrate. Our results propose a simple yet efficient way for exciton tuning in monolayer WSe2, which plays a central role in the fundamental understanding and further device development.
AB - We report large exciton tuning in WSe2 monolayers via substrate induced non-degenerate doping. We observe a redshift of ∼62 meV for the A exciton together with a 1-2 orders of magnitude photoluminescence (PL) quenching when the monolayer WSe2 is brought in contact with highly oriented pyrolytic graphite (HOPG) compared to dielectric substrates such as hBN and SiO2. As the evidence of doping from HOPG to WSe2, a drastic increase of the intensity ratio of trions to neutral excitons was observed. Using a systematic PL and Kelvin probe force microscopy (KPFM) investigation on WSe2/HOPG, WSe2/hBN, and WSe2/graphene, we conclude that this unique excitonic behavior is induced by electron doping from the substrate. Our results propose a simple yet efficient way for exciton tuning in monolayer WSe2, which plays a central role in the fundamental understanding and further device development.
UR - https://www.mendeley.com/catalogue/185e4bf9-c3ad-369c-8e46-9eec3e45d217/
U2 - 10.1039/d2na00495j
DO - 10.1039/d2na00495j
M3 - Article
C2 - 36504751
VL - 4
SP - 5102
EP - 5108
JO - Nanoscale Advances
JF - Nanoscale Advances
SN - 2516-0230
IS - 23
ER -
ID: 43512812