CoSb3-Based Thin-Film Thermoelectric Devices with High Performance Via Electrode Optimization

Flexible thin-film thermoelectric devices have been extensively studied for powering wearable electronics, particularly as a power source for self-powered sensors or temperature detection. Skutterudite CoSb3 is emerging as one of the most studied candidate materials for thermoelectric applications. This work is focused on comprehensive optimization in terms of CoSb3-based thin films as well as electrode materials and structures with the objective to fabricate high-performance flexible devices. CoSb3-based thin films with nanoparticles for the enhancement of phonon scattering have been fabricated using the vacuum sputtering method. N-type and P-type thin films can be obtained by appropriate doping with Ti and In, respectively. It has been demonstrated that a multilayer structure of electrodes can greatly enhance the thermoelectric performance of thermoelectric devices by increasing the output power and the thermal stability of the device in the air atmosphere. It has also been demonstrated the possibility of obtaining a relatively high output voltage of above 90 mV and a high-power density of 0.46 mW/cm2 at a current intensity of about 0.35 mA with the device. Therefore, many applications can be considered. The thin-film thermoelectric device has also been tested as a thermal sensor, and it exhibits fast responsivity, with a reaction time of a few hundreds of milliseconds, as well as high stability.