title: Spatially Resolved Electronic Properties of Single-Layer WS2on Transition Metal Oxides.
abstract: There is a substantial interest in the heterostructures of semiconducting transition metal dichalcogenides (TMDCs) among each other or with arbitrary materials, through which the control of the chemical, structural, electronic, spintronic, and optical properties can lead to a change in device paradigms. A critical need is to understand the interface between TMDCs and insulating substrates, for example, high-κ dielectrics, which can strongly impact the electronic properties such as the optical gap. Here, we show that the chemical and electronic properties of the single-layer (SL) TMDC, WS2, can be transferred onto high-κ transition metal oxide substrates TiO2and SrTiO3. The resulting samples are much more suitable for measuring their electronic and chemical structures with angle-resolved photoemission than their native-grown SiO2substrates. We probe the WS2on the micron scale across 100 μm flakes and find that the occupied electronic structure is exactly as predicted for free-standing SL WS2with a strong spin-orbit splitting of 420 meV and a direct band gap at the valence band maximum. Our results suggest that TMDCs can be combined with arbitrary multifunctional oxides, which may introduce alternative means of controlling the optoelectronic properties of such materials.
authors: Advanced Light Source, E.O. Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors: Søren
authors: S
authors: Ulstrup
authors: Department of Physics, The Ohio State University , Columbus, Ohio 43210, United States.
authors: Jyoti
authors: J
authors: Katoch
authors: Advanced Light Source, E.O. Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors: Roland J
authors: RJ
authors: Koch
authors: Advanced Light Source, E.O. Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors: Daniel
authors: D
authors: Schwarz
authors: Department of Physics, The Ohio State University , Columbus, Ohio 43210, United States.
authors: Simranjeet
authors: S
authors: Singh
authors: Naval Research Laboratory , Washington, D.C. 20375, United States.
authors: Kathleen M
authors: KM
authors: McCreary
authors: Advanced Light Source, E.O. Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors: Hyang Keun
authors: HK
authors: Yoo
authors: Department of Physics, The Ohio State University , Columbus, Ohio 43210, United States.
authors: Jinsong
authors: J
authors: Xu
authors: Naval Research Laboratory , Washington, D.C. 20375, United States.
authors: Berend T
authors: BT
authors: Jonker
authors: Department of Physics, The Ohio State University , Columbus, Ohio 43210, United States.
authors: Roland K
authors: RK
authors: Kawakami
authors: Advanced Light Source, E.O. Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors: Aaron
authors: A
authors: Bostwick
authors: Advanced Light Source, E.O. Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors: Eli
authors: E
authors: Rotenberg
authors: Advanced Light Source, E.O. Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors: Chris
authors: C
authors: Jozwiak
keywords: ARPES; PEEM; WS2; high-κ oxides; spatially resolved photoemission; transition metal dichalcogenides