Growth and characterization of large area MoS2 thin film

Abstract

Monolayer molybdenum disulfide (MoS2), a direct bandgap 2D crystal, has been

receiving great attention due to their unique electrical properties and potential in

optoelectronics. Many exciting devices can be fabricated if high quality and large

scale synthesis of these layers are possible. Mechanical exfoliation is the most

commonly used method to prepare MoS2 monolayers. However, the size of the layers

produced is limited and it restricts its application in a commercially viable device.

Many methods such as liquid exfoliation, physical vapour deposition and

electrochemical synthesis have since been proposed to synthesize MoS2 monolayers.

Recently, chemical vapour deposition methods have shown great promise in the

synthesis of large and highly crystalline atomic MoS2 layers. In this project, MoS2

layers had been grown with the chemical vapour deposition (CVD) method of

sulfurization of molybdenum trioxide (MoO3). The growth process was conducted

with different temperature and time to investigate their effects on the growth process.

The synthesized MoS2 layers had been characterized with optical microscope, Raman

spectroscopy, photoluminescence (PL) spectroscopy and atomic force microscopy

(AFM). The results have shown that MoS2 thin films had been successfully

synthesized. The edge length of the films increased with the temperature applied

while the relationship of the growth time to the growth of MoS2 is yet to be fully

determined, this may need more work done in the future.