Energy devices generating and storing electricity from finger and solar thermal energy

In this study, we demonstrate an energy device that consists of a thermoelectric generator (TEG) and a micro supercapacitor (MSC); electricity generated by the TEG is directly stored in the MSC. In this energy device, an interdigitated MSC is directly linked to a ring-patterned TEG with 80 pn modules that consist of p-Ag₂Te and n-Ag₂Se thin films. The ring-patterned TEG is designed for the effective use of thermal energy; a circular metal pad is added in its central area to maximize the absorption of thermal energy from a finger and from solar heat. The voltage of the MSC is rapidly raised up to 169 mV at a temperature difference of 8.6 K for the ring-patterned TEG; a volumetric energy density of 1.1 mJ/cm³ and a power density of 89.5 mW/cm³ are exhibited. In addition, our ring-patterned energy device generates and stores a voltage of 100 mV from the thermal energy of a finger with a raising rate of 0.1 V/min. Moreover, we examine the feasibility of the energy device consisting of a metal pad coated with solar-heat-absorption material when sunlight is used as the thermal energy source.