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arXiv · 2103.14382

Two-dimensional ReS2: Solution to the Unresolved Queries on Its Structure and Inter-layer Coupling Leading to Potential Optical Applications

Janardhan Rao Gadde+·Anasuya Karmakar+·Tuhin Kumar Maji+·Subhrajit Mukherjee·Rajath Alexander·Anjanashree M R Sharma·Sarthak Das·Anirban Mondal·Kinshuk Dasgupta·Akshay Naik·Kausik Majumdar·Ranjit Hawaldar·K V Adarsh·Samit Kumar Ray·Debjani Karmakar
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Abstract

Over the last few years, ReS2 has generated a myriad of unattended queries regarding its structure, the concomitant thickness dependent electronic properties and apparently contrasting experimental optical response. In this work, with elaborate first-principles investigations, using density functional theory (DFT) and time-dependent DFT (TDDFT), we identify the structure of ReS2, which is capable of reproducing and analyzing the layer-dependent optical response. The theoretical results are further validated by an in-depth structural, chemical, optical and optoelectronic analysis of the large-area ReS2 thin films, grown by chemical vapor deposition (CVD) process. Micro-Raman (MR), X-ray photoelectron spectroscopy (XPS), cross-sectional transmission electron microscopy (TEM) and energy-dispersive X-ray analysis (EDAX) have enabled the optimization of the uniform growth of the CVD films. The correlation between the layer-dependent optical and electronic properties of the excited states was established by static photoluminescence (PL) and transient absorption (TA) measurements. Sulfur vacancy-induced localized mid-gap states render a significantly long life-time of the excitons in these films. The ionic gel top-gated photo-detectors, fabricated from the as-prepared CVD films, exhibit a large photo-response of ~ 5 A/W and a remarkable detectivity of ~ 1011 Jones. The outcome of the present work will be useful to promote the application of vertically grown large-area films in the field of optics and opto-electronics.

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Janardhan Rao Gadde+, Anasuya Karmakar+, Tuhin Kumar Maji+, Subhrajit Mukherjee, Rajath Alexander, Anjanashree M R Sharma, Sarthak Das, Anirban Mondal, Kinshuk Dasgupta, Akshay Naik, Kausik Majumdar, Ranjit Hawaldar, K V Adarsh, Samit Kumar Ray, Debjani Karmakar. 2021-03-26. Two-dimensional ReS2: Solution to the Unresolved Queries on Its Structure and Inter-layer Coupling Leading to Potential Optical Applications. https://doi.org/10.1103/physrevmaterials.5.054006

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