High-Performance Flexible Thermoelectric Power Generator Using Laser Multiscanning Lift-Off Process

Abstract

Flexible thermoelectric generators (f-TEGs) are emerging as a semipermanent power source for self-powered sensors, which is an important area of research for next-generation smart network monitoring systems in the Internet-of-things era. We report in this paper a f-TEG produced by a screen-printing technique (SPT) and a laser multiscanning (LMS) lift-off process. A screen-printed TEG was fabricated on a SiO₂/a-Si/quartz substrate via the SPT process, and the LMS process completely separated the rigid quartz substrate from the original TEG by selective reaction of the XeCl excimer laser with the exfoliation layer (a-Si). Using these techniques, we fabricate a prototype f-TEG composed of an array of 72 TE couples that exhibits high flexibility at various bending radii, together with excellent output performance (4.78 mW/cm² and 20.8 mW/g at ΔT = 25 °C). There is no significant change in the device performance even under repeated bending of 8000 cycles.

Keywords: freestanding and flexible thermoelectric power generator; laser multiscanning lift-off process; screen-printing technique.