| AVS 63rd International Symposium & Exhibition | |
| 2D Materials Focus Topic | Friday Sessions |
| Session 2D+NS-FrM |
| Session: | 2D Materials: Device Physics and Applications |
| Presenter: | Christopher Muratore, University of Dayton |
| Authors: | M.E. McConney, Air Force Research Laboratory N.R. Glavin, Air Force Research Laboratory A.T. Juhl, Air Force Research Laboratory J.E. Bultman, University of Dayton Research Institute/Air Force Research Laboratory J.J. Hu, University of Dayton Research Institute/Air Force Research Laboratory M.F. Durstock, Air Force Research Laboratory A.A. Voevodin, University of North Texas C. Muratore, University of Dayton |
| Correspondent: | Click to Email |
Ultra-thin two-dimensional (2D) semiconducting materials possess a combination of large, tunable electronic bandgaps, optical transparency, and mechanical flexibility, and will likely revolutionize electronic devices such as wearable sensors and flexible displays. A primary step in the development of such devices with integrated 2D materials is the development of scalable, transfer-free synthesis over large areas at low temperatures. Electrically insulating amorphous transition metal dichalcogenide (TMD) films can be deposited via physical vapor deposition on large area flexible substrates at room temperature, and crystallized with subsequent illumination with light. Focused laser light with a power density of ~1 kW cm2is suitable for writing micron scale features in semiconducting transition metal dichalcogenides on polymer substrates. Broad band illumination from a xenon lamp can also be used over the large substrate areas (> 100 cm2), or passed through a physical mask to print features only in desired locations. The semiconducting properties of 2D MoS2 and WS2 materials synthesized in this way have been characterized using conductive atomic force microscopy, and other techniques to observe the expected temperature dependence on electrical conductivity. Structure and composition of the materials can be controlled by altering the incident fluence as well as by controlling the ambient environment during illumination, as verified by Raman spectroscopy, X-ray photoelectron spectroscopy, cross-sectional and plan view transmission electron spectroscopy, and other techniques. Multiple layers of 2D materials can also be treated in this way. For example, both layers in a MoS2/WS2 heterostructure of 10 nm total thickness on a polymer (PDMS) substrate were crystallized upon laser illumination. Diverse 2D architectures and devices built from illumination-based crystallization techniques will be highlighted.