TITLE: Electrochemical growth of telluride compounds and preparation of tiny thermoelectric energy conversion devicesDATE: 10.00am, May 18, 2018.
SPEAKER: Dr. Guodong Li
ADDRESS: The 314 meeting room of North Building
Abstract:
Thermoelectric materials of Tellurium (Te) and its based compounds as the n-type and p-type materials, possess the best thermoelectric figure-of-merit in the temperature range of room temperature up to 200 °C. Preparing thick and compact Telluride films with thickness in the range of tens of micrometers by electrochemical deposition (ECD) allows to realize on-chip integration of thermoelectric devices. ECD offers additional advantages regarding up-scalability, cost effective processing, and compatibility with microelectromechanical systems processing.
In our work, we firstly put efforts on growing thick and compact Telluride films for both n- and p- type materials by ECD technique. Secondly, various measurement techniques (in-situ and ex-situ) are utilized to characterize the thermoelectric transport properties, which are further analyzed to tune the ECD parameters to optimize the material properties. Thirdly, integrated micro- thermoelectric coolers (μTECs), with a leg pair packing density over 5000/cm2 are successfully fabricated by combining conventional techniques of ECD and photolithography. Long-term performance and stability of the as-fabricated μTECs are systematically studied using a CCD-based thermoreflectance imaging setup. Finally, model simulations based on finite-element method show consistency with the experimental results, indicating high quality thermoelectric materials (for both n and p legs) and negligible contact resistances in the as-fabricated μTECs.
Dr. Guodong Li received his PhD from National Center for Nanoscience and Technology (NCNST), Chinese Academy of Sciences in 2011 and started his postdoc research in Case Western Reserve University (USA) from 2011 to 2013. From 2013 to now, he has been working at Leibnitz Institute for Solid State and Material Research, Dresden, Germany. His research spans from electron transport properties in 2D electron gas to thermal transport properties of nanowires, thin films, and micro-scale energy conversion devices based on thermoelectric materials.
