TY - JOUR
T1 - Quantum-Confined Stark Effect of Individual Defects in a van der Waals Heterostructure
AU - Chakraborty, Chitraleema
AU - Goodfellow, Kenneth M.
AU - Dhara, Sajal
AU - Yoshimura, Anthony
AU - Meunier, Vincent
AU - Vamivakas, A. Nick
N1 - Funding Information:
This work was supported by NSF EFRI EFMA-1542707, NSF CAREER DMR 1553788, AFOSR FA9550-16-1-0020 and University of Rochester University Research Award.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/4/12
Y1 - 2017/4/12
N2 - The optical properties of atomically thin semiconductor materials have been widely studied because of the isolation of monolayer transition metal dichalcogenides (TMDCs). They have rich optoelectronic properties owing to their large direct bandgap, the interplay between the spin and the valley degree of freedom of charge carriers, and the recently discovered localized excitonic states giving rise to single photon emission. In this Letter, we study the quantum-confined Stark effect of these localized emitters present near the edges of monolayer tungsten diselenide (WSe2). By carefully designing sequences of metallic (graphene), insulating (hexagonal boron nitride), and semiconducting (WSe2) two-dimensional materials, we fabricate a van der Waals heterostructure field effect device with WSe2 hosting quantum emitters that is responsive to external static electric field applied to the device. A very efficient spectral tunability up to 21 meV is demonstrated. Further, evaluation of the spectral shift in the photoluminescence signal as a function of the applied voltage enables us to extract the polarizability volume (up to 2000 Å3) as well as information on the dipole moment of an individual emitter. The Stark shift can be further modulated on application of an external magnetic field, where we observe a flip in the sign of dipole moment possibly due to rearrangement of the position of electron and hole wave functions within the emitter.
AB - The optical properties of atomically thin semiconductor materials have been widely studied because of the isolation of monolayer transition metal dichalcogenides (TMDCs). They have rich optoelectronic properties owing to their large direct bandgap, the interplay between the spin and the valley degree of freedom of charge carriers, and the recently discovered localized excitonic states giving rise to single photon emission. In this Letter, we study the quantum-confined Stark effect of these localized emitters present near the edges of monolayer tungsten diselenide (WSe2). By carefully designing sequences of metallic (graphene), insulating (hexagonal boron nitride), and semiconducting (WSe2) two-dimensional materials, we fabricate a van der Waals heterostructure field effect device with WSe2 hosting quantum emitters that is responsive to external static electric field applied to the device. A very efficient spectral tunability up to 21 meV is demonstrated. Further, evaluation of the spectral shift in the photoluminescence signal as a function of the applied voltage enables us to extract the polarizability volume (up to 2000 Å3) as well as information on the dipole moment of an individual emitter. The Stark shift can be further modulated on application of an external magnetic field, where we observe a flip in the sign of dipole moment possibly due to rearrangement of the position of electron and hole wave functions within the emitter.
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U2 - 10.1021/acs.nanolett.6b04889
DO - 10.1021/acs.nanolett.6b04889
M3 - Article
C2 - 28267348
AN - SCOPUS:85017560901
SN - 1530-6984
VL - 17
SP - 2253
EP - 2258
JO - Nano letters
JF - Nano letters
IS - 4
ER -