Tuning Interlayer Exciton Emission with TMD Alloys in van der Waals Heterobilayers of Mo0.5W0.5Se2 and Its Binary Counterparts
Semiconductor heterostructures have been the backbone of developments in electronic and optoelectronic devices. One class of structures of interest is the so-called type II band alignment, in which optically excited electrons and holes relax into different material layers. The unique properties o...
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| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Philipps-Universität Marburg
2023
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| Subjects: | |
| Online Access: | PDF Full Text |
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| Summary: | Semiconductor heterostructures have been the backbone of developments in electronic and
optoelectronic devices. One class of structures of interest is the so-called type II band alignment,
in which optically excited electrons and holes relax into different material layers. The unique
properties observed in two-dimensional transition metal dichalcogenides and the possibility to
engineer van der Waals heterostructures make them candidates for future high-tech devices. In
these structures, electronic, optical, and magnetic properties can be tuned through the interlayer
coupling, thereby opening avenues for developing new functional materials. We report the possibility
of explicitly tuning the emission of interlayer exciton energies in the binary–ternary heterobilayer
of Mo0.5W0.5Se2 with MoSe2 and WSe2. The respective interlayer energies of 1.516 eV and 1.490 eV
were observed from low-temperature photoluminescence measurements for the MoSe2– and WSe2–
based heterostructures, respectively. These interlayer emission energies are above those reported
for MoSe2/WSe2 ('1.30–1.45 eV). Consequently, binary–ternary heterostructure systems offer an
extended energy range and tailored emission energies not accessible with the binary counterparts.
Moreover, even though Mo0.5W0.5Se2 and MoSe2 have almost similar optical gaps, their band offsets
are different, resulting in charge transfer between the monolayers following the optical excitation.
Thus, confirming TMDs alloys can be used to tune the band-offsets, which adds another design
parameter for application-specific optoelectronic devices. |
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| Item Description: | Gefördert durch den Open-Access-Publikationsfonds der UB Marburg. |
| Physical Description: | 14 Pages |
| DOI: | 10.3390/nano13202769 |