Optimization of Power Factor for a Screen-Printed Silver Selenide-Based Flexible Thermoelectric Film by Hot Pressing

Screen printing is a promising technology to realize the large-scale production of flexible thermoelectric films, and Ag2Se is considered as the upcoming generation of room-temperature N-type thermoelectric materials that can substitute N-type Bi2Te3-based alloys. However, since the reported screen-printed Ag2Se-based flexible films were not properly sintered, their thermoelectric performance is far from satisfactory. In this work, hot pressing technology is applied to sinter the nylon-supported flexible Ag/Ag2Se thermoelectric films, and the carrier transport characteristics and power factor of the films were optimized by adjusting the hot pressing pressure and duration. For the film hot-pressed with 40 MPa and 10 min, a high power factor of 3002.14 μWm–1K–2 has been achieved at 303 K. This film also shows an excellent flexibility, and with a bending radius of 1.5 cm, the internal resistance of the film changes little after being bent 500 times. This work provides a feasible idea for improving the thermoelectric performance of Ag2Se-based films prepared by screen printing.