2018 AIChE Annual Meeting
(66d) Fabrication of Transition Metal Chalcogenide Cu2Se Semiconducting Thin Films and Thermoelectric Property Characterization
Author
The goal of this work is to determine reliable, low-energy and low-cost routes of fabricating Cu2Se thin films with high figure of merit, ZT, which quantifies the thermoelectric performance of a material. To obtain a high ZT value, both Seebeck coefficient and electrical conductivity must be large and thermal conductivity should be minimized. This is fundamentally difficult to achieve because reduction in thermal conductivity is typically accompanied by a large penalty to electrical conductivity. Nanostructured materials and thin films can potentially break this relationship between the electronic and thermal properties of a material. We adopt two methods of making Cu2Se thin films: 1) Directly fabricate nanostructured Cu2Se thin films using a solvent deposition process and dope the films; 2) Using a cation exchange process using cadmium selenide nanocrystals. We perform structural characterization of our thin films via x-ray diffraction and scanning electron microscopy. Through electrical conductivity and Seebeck coefficient measurements, we compare their thermoelectric properties and optimize ZT values by varying their chemical composition and film morphology.