Electrodeposited Thin-Film Micro-Thermoelectric Coolers with Extreme Heat Flux Handling and Microsecond Time Response
Simon Corbett, Devendraprakash Gautam, Swatchith Lal, Kenny Yu, Naveen K. Balla, G.W. Cunningham, Kafil M. Razeeb, Ryan Enright, David McCloskey
Abstract
Thin-film thermoelectric coolers are emerging as a viable option for the on-chip temperature management of electronic and photonic integrated circuits. In this work, we demonstrate the record heat flux handling capability of electrodeposited Bi2Te3 films of 720(±60) W cm–2 at room temperature, achieved by careful control of the contact interfaces to reduce contact resistance. The characteristic parameters of a single leg thin-film devices were measured in situ, giving a Seebeck coefficient of S = −121(±6) μV K–1, thermal conductivity of κ = 0.85(±0.08) W m–1 K–1, electrical conductivity of σ = 5.2(±0.32) × 104 S m–1, and electrical contact resistivity of ∼10–11 Ω m2. These thermoelectric parameters lead to a material ZT = 0.26(±0.04), which, for our device structure, allowed a net cooling of ΔTmax = 4.4(±0.12) K. A response time of τ = 20 μs was measured experimentally. This work shows that with the correct treatment of contact interfaces, electrodeposited thin-film thermoelectrics can compete with more complicated and expensive technologies such as metal organic chemical vapor deposition (MOCVD) multilayers.