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HL: Fachverband Halbleiterphysik
HL 33: Poster II
HL 33.5: Poster
Wednesday, March 29, 2023, 17:00–19:00, P1
Stokes shift of twisted bilayer WSe2 — •Zihao Liu1, Yang Pan1,2, and Dietrich R. T. Zahn1,2 — 1Semiconductor Physics, Institute of Physics, Chemnitz University of Technology, Chemnitz, Germany — 2Center for Materials, Architectures, and Integration of Nanomembranes (MAIN), Chemnitz University of Technology, Chemnitz, Germany
Transition metal dichalcogenides (TMDCs) with a typical layered structure have exceptional optical properties exhibiting a characteristic absorption and emission at excitonic resonances. The weak van der Waals (vdW) interlayer coupling nature enables the possibility of artificial staking, leading to homo- and hetero-structures formation. It was demonstrated in our previous work that the optical properties can be strongly modified by the twisting angle.
Here, WSe2 monolayers (MLs) were obtained by mechanical exfoliation, which were then transferred onto sapphire substrates by a tear-and-stack method to form twisted homo-bilayers with a precision of 0.08°. We then performed optical transmission and photoluminescence (PL) experiments on monolayers, intrinsic bilayers and twisted bilayers to determine the Stokes shift values on a full period (0°-60°) of twisted bilayer WSe2.