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HL: Fachverband Halbleiterphysik
HL 42: 2D Materials 6 (joint session HL/CPP/DS)
HL 42.3: Talk
Friday, September 9, 2022, 10:00–10:15, H36
Atomic layer deposition of ternary MoWS2 — •Christian Tessarek, Tim Grieb, Andreas Rosenauer, and Martin Eickhoff — Institut für Festkörperphysik, Universität Bremen
Two-dimensional (2D) monolayers of binary molybdenum disulfide (MoS2) and tungsten disulfide (WS2) belong to the transition metal dichalcogenide (TMDC) material family and are direct band gap semiconductors. The optical band gap of monolayer MoS2 and WS2 is ∼1.9 and 2.0 eV, respectively. Ternary MoxW1−xS2 enables tuning of excitonic transition energy dependent on the concentration x.
Atomic layer deposition (ALD) is used to deposit MoWS2 in the whole composition range between pure MoS2 and WS2. The concentration x is determined by the frequency position of the A1g Raman mode. The distribution of W and Mo atoms in the crystal lattice of MoWS2 is studied by high resolution scanning transmission electron microscopy. Additional annealing is performed to improve structural and optical properties. Photoluminescence spectroscopy measurements show concentration dependent spectral position of A and B excitonic emission.