Indium tin oxide thin films for textile-based thermoelectric devices

Abstract This study investigated indium tin oxide as an n-type thermoelectric material for textile-based energy harvesting. Comprehensive characterization revealed a strong influence of fabrication temperature on specific resistivity of the ITO films and on charge carrier mobility. The Seebeck coefficient (-20 to -30 µV/K) and thermal conductivity were also temperature dependent. X-ray diffraction confirmed crystalline ITO films with preferred (211) or (222) orientations. Optimized at 300 °C substrate temperature, the material exhibited power factors of 0.8–1.7 × 10⁻⁴ W/mK² and zT values ranging from 0.008 to 0.02 (at room temperature to 100 °C), respectively. This basic characterization enabled successful deposition of ITO onto textile fibers, maintaining comparable thermoelectric performance. A resulting textile-based thermo-electric generator demonstrated a five-fold power increase with a four-element stack, highlighting the benefits of series interconnection. Accurate temperature measurement, minimizing contact resistance and enhancing mechanical stability through encapsulation are identified as critical areas for future optimization to enhance device performance and durability.