Electrodeposited Thin-Film Micro-Thermoelectric Coolers with Extreme Heat Flux Handling and Microsecond Time Response

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 Bi 2 Te 3 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) × 10 4 S m –1, and electrical contact resistivity of ∼10 –11 Ω m 2 . These thermoelectric parameters lead to a material ZT = 0.26(±0.04), which, for our device structure, allowed a net cooling of Δ T max = 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.