Growth and Properties of 2D Layered Semiconductors

Layered transition metal dichalcogenide materials are a family of semiconductors having a wide range of energy band gaps and properties, with the potential to explore exciting new physics and technological applications, specifically energy efficient and low power consumption logic circuits. However, obtaining high crystal quality thin films over a large area remains a challenge. In this talk, we will present that a simple chemical vapor deposition (CVD) method can be used to achieve large area single crystal Molybdenum Disulfide (MoS2) few nm thick thin films. Growth temperature and choice of substrate were found to critically impact the quality of film grown, and high temperature growth on (0001) orientated sapphire yielded highly oriented single crystal MoS2 films. Photoluminescence and electrical measurements confirmed the growth of optically active MoS2 with a low background carrier concentration, and high mobility. This CVD approach paves the way towards growth of a variety of other layered 2D chalcogenide semiconductors and their heterostructures.