Thermoelectric infrared detectors: Design, fabrication, and performance assessment

This study presents a comprehensive optimization and comparative analysis of thermoelectric (TE) infrared (IR) detectors using Bi2Te3 and Si materials. Through theoretical modeling and numerical simulations, we explored the impact of TE material properties, device structure, and operating conditions on responsivity, detectivity, noise equivalent temperature difference (NETD), and noise equivalent power (NEP). Our study offers an optimally designed IR detector with responsivity and detectivity approaching 2 x 10(5) V/W and 6 x 10(9) cm center dot Hz(1/2)/W, respectively. This enhancement is attributed to unique design features, including raised thermal collectors and long suspended thin thermoelectric wire sensing elements embedded in low thermal conductivity organic materials like parylene. Moreover, we demonstrate the compatibility of Bi2Te3-based detector fabrication processes with existing MEMS foundry processes, facilitating scalability and manufacturability. Importantly, for TE IR detectors, zT/kappa emerges as a critical parameter contrary to conventional TE material selection based solely on zT (where zT is the thermoelectric figure of merit and kappa is the thermal conductivity).