Assembly-Free Fabrication of High-Performance Flexible Inorganic Thin-Film Thermoelectric Device Prepared by a Thermal Diffusion

High relative contact electrical resistance and poor flexibility in inorganic thin-film thermoelectric devices significantly limit their practical applications. To overcome this challenge, a one-step thermal diffusion method to fabricate assembly-free inorganic thin-film thermoelectric devices is developed, where the in situ grown electrode delivers an excellent leg-electrode contact, leading to high output power and flexibility in the prepared p-type Sb2Te3/n-type Bi2Te3 thin-film device, which is composed of 8 pairs of p-n junctions. Such a device shows a very low relative contact electrical resistance of 7.5% and a high power density of 1.42 mW cm(-2) under a temperature difference of 60 K. Less than 10% change of the whole electrical resistance before and after bending test indicates the robust bending resistance and stability of the device. This study indicates that the novel assembly-free one-step thermal diffusion method can effectively enhance the leg-electrode contact, the device thermoelectric performance, bending resistance, and stability, which can inspire the development of thin-film thermoelectric devices.