Investigation of two dimensional material production with spark erosion

Abstract

This project examines the possibility to produce material of two dimensions with the electrochemical method of spark erosion. Three transition metal dichalcogenides were examined, namely MoS2, MoSe2 and WS2. Their layered crystal structure and semiconductor behavior make them interesting for nanoelectronic devices. The method of spark erosion could give a cost efficient and large scale production method.Spark erosion has previously shown to be a very effective method to exfoliate nanoparticles. This project investigates the possibility to reduce the dimensions of the produced material and create 2D nanoflakes. The project includes a thorough description of the experiments conducted. Many different fields and methods were examined in order to find reliable results and conclusions. It includes electrophysics and electrochemisty, as well as nanosize characterization. The setup used to support spark erosion have been adjusted and altered to support the production of 2D materials, but it has not been optimized. It was possible to produce microparticles of WS2 but no single layer material was observed. A challenge was to separate the particles from the dielectric liquid of the setup, namely oleic acid. Centrifugation and chemical cleaning was used. To further examine the 2D material production with spark erosion the current and voltage of the setup needs to be tuned more precisely. This will effect the energy which is used to exfoliate the material.