Humidity‐Controlled Ultralow Power Layer‐by‐Layer Thinning, Nanopatterning and Bandgap Engineering of MoTe2
Abstract
A highly effective laser thinning method is demonstrated to accurately control the thickness of MoTe2 layers. By utilizing the humidity present in the ambient atmosphere, multilayered MoTe2 films can be uniformly thinned all the way down to monolayer with layer‐by‐layer precision using an ultralow laser power density of 0.2 mW µm−2. Localized bandgap engineering is also performed in MoTe2, by creating regions with different bandgaps on the same film, enabling the formation of lateral homojunctions with sub‐200 nm spatial resolution. Field‐effect transistors fabricated from these thinned layers exhibit significantly improved electrical properties with an order of magnitude increase in on/off current ratios, along with enhancements in on‐current and field‐effect mobility values. Thinned devices also exhibit the fastest photoresponse (45 µs) for an MoTe2‐based visible photodetector reported to date, along with a high photoresponsivity. A highly sensitive monolayer MoTe2 photodetector is also reported. These results demonstrate the efficiency of the presented thinning approach in producing high‐quality MoTe2 films for electronic and optoelectronic applications.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 12, 2018
- Source ID
- 10.1002/adfm.201804434
Entities
People
- C D Wright
- Monica F. Craciun
- Nicola J. Townsend
- Saverio Russo
- Toby J. Octon
- V. Karthik Nagareddy
Organizations
- Engineering and Physical Sciences Research Council
- Office of Naval Research Global
- University of Exeter