Combinatorial Large-area MoS2/Anatase-TiO2 interface: A Pathway to Emergent Optical and Opto-electronic Functionalities
Autor: | Ranjit Hawaldar, Samir Kumar Pal, Sarthak Das, Tuhin Kumar Maji, Anirban Mondal, Samit K. Ray, Aswin J. R, Anjanashree M. R. Sharma, Manjiri Pandey, Akshay Naik, Naba Kumar Chakraborty, Kinshuk Dasgupta, Rajendra Kumar Sharma, Kausik Majumdar, Debjani Karmakar, K. V. Adarsh, Subhrajit Mukherjee, Rajath Alexander |
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Rok vydání: | 2021 |
Předmět: |
Anatase
Condensed Matter - Materials Science Materials science business.industry Interface (Java) Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences 02 engineering and technology Electronic structure Dielectric 021001 nanoscience & nanotechnology 01 natural sciences symbols.namesake 0103 physical sciences symbols Optoelectronics General Materials Science P type doping 010306 general physics 0210 nano-technology business Raman scattering |
DOI: | 10.48550/arxiv.2101.11941 |
Popis: | Interface of transition metal dichalcogenide (TMDC) and high-k dielectric transition metal oxides (TMO) had triggerred umpteen discourses due to the indubitable impact of TMO 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 (PLD) MoS2 thin film, a layer of TiO2 is grown by using both atomic layer deposition (ALD) and PLD. These two different techniques emanate TiO2 layers with different crystalline properties, thicknesses and interfacial morphologies, subsequently influencing the electronic and optical properties of the interfaces. In addition, they manifest a boost in the extent of p-type doping with increasing thickness of TiO2, as emerged after analyzing the core-level shifts of the X-ray photoelectron spectra (XPS). Density functional analysis of the MoS2/Anatase-TiO2 interfaces, for pristine and in presence of a wide range of interfacial defects, could explain the interdependence of doping and the terminating atomic-surface of TiO2 on MoS2. The optical properties of the interface, encompassing the photoluminescence, transient absorption and z-scan two-photon absorption indicate the presence of defect-induced localized mid-gap levels in MoS2/TiO2 (PLD), resulting quenched exciton signals. On the contrary, the relatively defect-free interface in MoS2/TiO2 (ALD) demonstrates a clear presence of both A and B excitons of MoS2. From the investigation of optical properties, we indicate that MoS2/TiO2 (PLD) interface may act as a promising saturable absorber. Moreover, MoS2/TiO2 (PLD) interface had resulted a better photo-transport. A potential application of MoS2/TiO2 (PLD) is demonstrated by the fabrication of a p-type photo-transistor with the ionic-gel top gate. |
Databáze: | OpenAIRE |
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