Spatially Resolved Electronic Properties of Single-Layer WS2 on Transition Metal Oxides

TY - JOUR

T1 - Spatially Resolved Electronic Properties of Single-Layer WS2 on Transition Metal Oxides

AU - Ulstrup, Søren

AU - Katoch, Jyoti

AU - Koch, Roland J.

AU - Schwarz, Daniel

AU - Singh, Simranjeet

AU - McCreary, Kathleen M.

AU - Yoo, Hang Keun

AU - Xu, Jinsong

AU - Jonker, Berend T.

AU - Kawakami, Roland K.

AU - Bostwick, Aaron

AU - Rotenberg, Eli

AU - Jozwiak, Chris

PY - 2016/11/22

Y1 - 2016/11/22

N2 - 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, WS 2, can be transferred onto high-κ transition metal oxide substrates TiO 2 and SrTiO 3. The resulting samples are much more suitable for measuring their electronic and chemical structures with angle-resolved photoemission than their native-grown SiO 2 substrates. We probe the WS 2 on the micron scale across 100 μm flakes and find that the occupied electronic structure is exactly as predicted for free-standing SL WS 2 with 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.

AB - 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, WS 2, can be transferred onto high-κ transition metal oxide substrates TiO 2 and SrTiO 3. The resulting samples are much more suitable for measuring their electronic and chemical structures with angle-resolved photoemission than their native-grown SiO 2 substrates. We probe the WS 2 on the micron scale across 100 μm flakes and find that the occupied electronic structure is exactly as predicted for free-standing SL WS 2 with 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.

KW - ARPES

KW - PEEM

KW - WS

KW - high-κ oxides

KW - spatially resolved photoemission

KW - transition metal dichalcogenides

UR - https://www.scopus.com/pages/publications/84997284744

U2 - 10.1021/acsnano.6b04914

DO - 10.1021/acsnano.6b04914

M3 - Journal article

SN - 1936-0851

VL - 10

SP - 10058

EP - 10067

JO - ACS Nano

JF - ACS Nano

IS - 10058

M1 - 10058

ER -