Flexible thermoelectric power generators based on electrochemical deposition process of BI2TE3 and SB2TE3

The harvest of thermal energy using thermoelectric (TE) effect is one of the potential methods for wearable devices. This paper demonstrates a new approach of electrochemical deposition to fabricate flexible thermoelectric generators (FTEGs). Two proposed structures have been developed to compare the performance of the devices. One is the π-type flexible devices with thick thermoelectric cells in micro scale and the other is a new lateral Y-type structure for FTEGs. For the first time, the electrochemical deposition of thermoelectric materials Bi₂Te₃ and Sb₂Te₃ is used to integrate thermoelectric materials inside the flexible structures. The Seebeck coefficients of Bi₂Te₃ and Sb₂Te₃ are -150±20 and 170±20 μν/K, respectively. Additionally, the electrical resistivity of Bi₂Te₃ shows 15±5 μΩm while that of Sb₂Te₃ is 25±5 μΩm. The thicknesses of each thermocouple (TCs) are approximately 100 μm and 200 μm for Y-type and π-type, respectively. With the temperature difference approximately 22°C between human body (around 37°C) and environment ambience (15°C), the lateral Y-type and vertical π-type devices generate maximum powers approximately 3 and 4 μW/cm², respectively.