| Autor: |
Maji, Tuhin Kumar, J. R, Aswin, Mukherjee, Subhrajit, Alexander, Rajath, Mondal, Anirban, Das, Sarthak, Sharma, Rajendra Kumar, Chakraborty, Naba Kumar, Dasgupta, Kinshuk, Sharma, Anjanashree M. R., Hawaldar, Ranjit, Pandey, Manjiri, Naik, Akshay, Majumdar, Kausik, Pal, Samir Kumar, Adarsh, K. V., Ray, Samit Kumar, Karmakar, Debjani |
| Zdroj: |
ACS Applied Materials & Interfaces; September 2020, Vol. 12 Issue: 39 p44345-44359, 15p |
| Abstrakt: |
The interface of transition-metal dichalcogenides (TMDCs) and high-kdielectric transition-metal oxides (TMOs) had triggered umpteen discourses because of the indubitable impact of TMOs in reducing the contact resistances and restraining the Fermi-level pinning for the metal–TMDC contacts. In the present work, we focus on the unresolved tumults of large-area TMDC/TMO interfaces, grown by adopting different techniques. Here, on a pulsed laser-deposited MoS2thin film, a layer of TiO2is grown by atomic layer deposition (ALD) and pulsed laser deposition (PLD). These two different techniques emanate the layer of TiO2with different crystallinities, thicknesses, and interfacial morphologies, subsequently influencing the electronic and optical properties of the interfaces. Contrasting the earlier reports of n-type doping at the exfoliated MoS2/TiO2interfaces, the large-area MoS2/anatase–TiO2films had realized a p-type doping of the underneath MoS2, manifesting a boost in the extent of p-type doping with increasing thickness of TiO2, as emerged from the X-ray photoelectron spectra. Density functional analysis of the MoS2/anatase–TiO2interfaces, with pristine and interfacial defect configurations, could correlate the interdependence of doping and the terminating atomic surface of TiO2on MoS2. The optical properties of the interface, encompassing photoluminescence, transient absorption and z-scan two-photon absorption, indicate the presence of defect-induced localized midgap levels in MoS2/TiO2(PLD) and a relatively defect-free interface in MoS2/TiO2(ALD), corroborating nicely with the corresponding theoretical analysis. From the investigation of optical properties, we indicate that the MoS2/TiO2(PLD) interface may act as a promising saturable absorber, having a significant nonlinear response for the sub-band-gap excitations. Moreover, the MoS2/TiO2(PLD) interface had exemplified better phototransport properties. A potential application of MoS2/TiO2(PLD) is demonstrated by the fabrication of a p-type phototransistor with the ionic-gel top gate. This endeavor to analyze and perceive the MoS2/TiO2interface establishes the prospectives of large-area interfaces in the field of optics and optoelectronics. |
| Databáze: |
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