Fabrication and Characterization of Ultra‐Lightweight, Compact, and Flexible Thermoelectric Device Based on Highly Refined Chip Mounting

Abstract Thermoelectric generators (TEGs) are a promising power source for realizing a self‐powered sensor, which is a primary component of the rapidly developing Internet of Things. Here, the fabrication of a prototype for a compact and flexible TEG (CF‐TEG) using ultra‐fine chip mounting technique is reported. The CF‐TEG consisting of 84 p‐n pairs was fabricated on a 10 × 10 mm² flexible substrate. A temperature difference (dT) of 150 K is successfully established for this TEG. Its maximum output voltage and power density are obtained as 2.4 V and 185 mW cm⁻², respectively, which corresponds to a conversion efficiency of 1.12% at dT = 150 K. Further, the experimental results are validated through theoretical analysis in which the contact effects are taken into account. This analysis is also used to elucidate the effect of thermal and electrical contact resistance on the output power. It is observed that ≈40% output power of this device is lost by these resistances, which proves that the contact properties significantly affect the performance of the TEG device.