Cooling property and application of Au–Bi₂Te₃ heterojunction nanowire array based on AAO template

In this work, selective radiation material was used to change heat transport of hot side, a novel heterostructure cooler, constructed by gold (Au)—bismuth telluride (Bi₂Te₃) nanowires array was reported experimentally. The heterostructure was fabricated by electrochemical deposition based on porous anodic alumina template (AAO). The Au nanowire cluster array is used as an infrared selective radiation surface to optimize heat transport of the heat side. And the Bi₂Te₃ nanowires generate thermoelectromotive force between the two sides of the device due to thermoelectric effect. More interestingly, the Au nanowire ends produce an interface between the metal and semiconductor to enhance the temperature difference, as the interfacial phonon scattering suppresses thermal conductivity. The co-effects create a linear-like relationship between the temperature difference and the applied heating strength to make the heating source hide from infrared detection. At a heating temperature of 170 °C, the radiation temperature difference arrives 16 °C in the Au–Bi₂Te₃ heterojunction, (increased by 200% to that in Bi₂Te₃ single phase), given by an intriguing demonstration of infrared camouflage effect. The Au–Bi₂Te₃ nanowires heterojunction device can not only realize infrared camouflage, but also convert the heat into electrical energy, which provides a new idea for the development of materials.