Excitation-Dependent High-Lying Excitonic Exchange via Interlayer Energy Transfer from Lower - to - Higher Bandgap 2D Material.
Arka KarmakarTomasz KazimierczukIgor AntoniazziMateusz RaczyńskiSu Ji ParkHouk JangTakashi TaniguchiKenji WatanabeAdam BabińskiAbdullah Al-MahboobMaciej R MolasPublished in: Nano letters (2023)
High light absorption (∼15%) and strong photoluminescence (PL) emission in monolayer (1L) transition metal dichalcogenides (TMDs) make them ideal candidates for optoelectronic device applications. Competing interlayer charge transfer (CT) and energy transfer (ET) processes control the photocarrier relaxation pathways in TMD heterostructures (HSs). In TMDs, long-distance ET can survive up to several tens of nm, unlike the CT process. Our experiment shows that an efficient ET occurs from the 1Ls WSe 2 -to-MoS 2 with an interlayer hexagonal boron nitride (hBN), due to the resonant overlapping of the high-lying excitonic states between the two TMDs, resulting in enhanced HS MoS 2 PL emission. This type of unconventional ET from the lower-to-higher optical bandgap material is not typical in the TMD HSs. With increasing temperature, the ET process becomes weaker due to the increased electron-phonon scattering, destroying the enhanced MoS 2 emission. Our work provides new insight into the long-distance ET process and its effect on the photocarrier relaxation pathways.
Keyphrases
- energy transfer
- quantum dots
- transition metal
- computed tomography
- room temperature
- image quality
- solar cells
- dual energy
- reduced graphene oxide
- magnetic resonance imaging
- contrast enhanced
- solid state
- positron emission tomography
- visible light
- photodynamic therapy
- magnetic resonance
- high resolution
- highly efficient
- pet ct
- gold nanoparticles
- high speed