Controlled Growth of large area bilayer MoS$_2$ films on SiO$_2$ substrates by chemical vapour deposition technique

Fuente: arXiv
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Autores principales: Patra, Umakanta, Mujeeb, Faiha, K, Abhiram, Israni, Jai, Dhar, Subhabrata
Formato: Preprint
Publicado: 2024
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author Patra, Umakanta
Mujeeb, Faiha
K, Abhiram
Israni, Jai
Dhar, Subhabrata
author_facet Patra, Umakanta
Mujeeb, Faiha
K, Abhiram
Israni, Jai
Dhar, Subhabrata
contents Bilayer (2L) transition metal dichalcogenides (TMD) have the ability to host interlayer excitons, where electron and hole parts are spatially separated that leads to much longer lifetime as compared to direct excitons. This property can be utilized for the development of exciton-based logic devices, which are supposed to be superior in terms of energy efficiency and optical communication compatibility as compared to their electronic counterparts. However, obtaining uniformly thick bilayer epitaxial films with large area coverage is challenging. Here, we have engineered the flow pattern of the precursors over the substrate surface to obtain large area (mm2) covered strictly bilayer MoS$_2$ films on SiO$_2$ by chemical vapour deposition (CVD) technique without any plasma treatment of the substrate prior to the growth. Bilayer nature of these films is confirmed by Raman, low-frequency Raman, atomic force microscopy (AFM) and photoluminescence (PL) studies. The uniformity of the film has been checked by Raman peak separation and PL intensity map. High resolution transmission electron microscopy (HRTEM) reveals that crystalline and twisted bilayer islands coexist within the layer. Back gated field-effect transistor (FET) structures fabricated on the bilayers show on/off ratio of 10^6 and subthreshold swings (SS) of 2.5 V/Decade.
format Preprint
id arxiv_https___arxiv_org_abs_2409_07921
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Controlled Growth of large area bilayer MoS$_2$ films on SiO$_2$ substrates by chemical vapour deposition technique
Patra, Umakanta
Mujeeb, Faiha
K, Abhiram
Israni, Jai
Dhar, Subhabrata
Materials Science
Mesoscale and Nanoscale Physics
Bilayer (2L) transition metal dichalcogenides (TMD) have the ability to host interlayer excitons, where electron and hole parts are spatially separated that leads to much longer lifetime as compared to direct excitons. This property can be utilized for the development of exciton-based logic devices, which are supposed to be superior in terms of energy efficiency and optical communication compatibility as compared to their electronic counterparts. However, obtaining uniformly thick bilayer epitaxial films with large area coverage is challenging. Here, we have engineered the flow pattern of the precursors over the substrate surface to obtain large area (mm2) covered strictly bilayer MoS$_2$ films on SiO$_2$ by chemical vapour deposition (CVD) technique without any plasma treatment of the substrate prior to the growth. Bilayer nature of these films is confirmed by Raman, low-frequency Raman, atomic force microscopy (AFM) and photoluminescence (PL) studies. The uniformity of the film has been checked by Raman peak separation and PL intensity map. High resolution transmission electron microscopy (HRTEM) reveals that crystalline and twisted bilayer islands coexist within the layer. Back gated field-effect transistor (FET) structures fabricated on the bilayers show on/off ratio of 10^6 and subthreshold swings (SS) of 2.5 V/Decade.
title Controlled Growth of large area bilayer MoS$_2$ films on SiO$_2$ substrates by chemical vapour deposition technique
topic Materials Science
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2409.07921