Discipline: Physics
Subcategory: Materials Science
Gilbert Kogo - Norfolk State University
Co-Author(s): Dr. Xiao, Bo; Dr Messoud Bahoura
Thermal energy harvesting that converts heat flux directly into electricity offers an attractive solution to meet our emerging demand for generating clean, renewable and scalable energy. Owing to the remarkable thermal and electrical properties, MoS2, especially in its thin film form has opened a new avenue for realizing scalable thermal harvesting devices. Here, we report on highly crystalline MoS2 thin films deposited by radio-frequency (rf) magnetron sputtering on a variety of substrates. Structural, thermal and electrical properties of the MoS2 thin films have been investigated systematically to develop high-efficient thermal harvesting devices. Crystal properties of MoS2 thin films measured by X-ray diffraction (XRD) and atomic force microscopy (AFM) revealed highly oriented (00l) thin films with homogeneous grain size ranging from 40 to 100 nm. Raman spectroscopy shows distinctive MoS2 vibrational modes of molybdenum and sulfur atoms at 380cm-1 for E12g and 410 cm-1 for A1g. Electrical and thermal studies further demonstrated that the MoS2 films shows p-type thermoelectric characteristics with Seebeck coefficient values between 300-400 µVK-1 at room temperature, also when the film was deposited on n-type silicon the rectifying behavior of ±0.5V and turn on voltage of 0.2V is observed.
Thermoelectric properties of epitaxial MoS2 t.docxFunder Acknowledgement(s): This work is supported by the NSF-CREST (CNBMD) Grant number HRD 1036494 and CREST-CREAM HRD-1547771
Faculty Advisor: Dr Messoud Bahoura, mbahoura@nsu.edu
Role: Everything