Single crystal flake parameters of MoS₂ and MoSe₂ exfoliated using anodic bonding technique and its potential in rapid prototyping

Abstract

Rapid prototyping of devices using exfoliated Molybednum di-Sulphide (MoS2) and Molybdenum di-Selenide (MoSe2) requires an experimental protocol for maximizing the probability of realizing flakes with desired physical dimension and properties. In this work, we analyzed the size and thickness distribution of MoS2 and MoSe2 single crystalline flakes exfoliated using anodic bonding technique and established a correlation between physical dimension of the flakes and the bonding parameters. Anodic bonding was carried out by applying a fixed voltage of 200 V with a set temperature of 150 °C for four different bonding time intervals. On analyzing the flake parameters from the four anodic bonded substrates using the optical and atomic force microscopy, it is found that the probability of getting flakes with large lateral size (>200 μm) increases as the bonding time interval is increased. Most of these large sized flakes have thickness of more than one hundred mono-layers and a tiny fraction of them have thickness of the order of few monolayers. A similar trend was also observed for MoSe2 single crystals. To demonstrate the feasibility of this technique in rapid prototyping, ultra thin MoS2 flakes was directly bridged between two ITO electrodes and their transport properties was investigated. Micro-Raman and photoluminescence studies were taken on selected regions of the thicker and thinner exfoliated flakes and their physical properties are compared.

MoS2 thin film decorated TiO2 nanotube arrays on flexible Ti foil for solar water splitting application

“…This method offers the production of large-area MoS 2 thin film with excellent quality and tunability of properties [28]. Even though techniques such as liquid exfoliation, scotch tape method, physical vapor deposition, hydrothermal method, etc, have been used to obtain high-quality MoS 2 layers/thin film [29][30][31][32]. Exfoliation techniques have limitations due to the long process time, nonrepeatability, and inability to produce large-area thin film.…”