Exploring Material Properties and Device Output Performance of a Miniaturized Flexible Thermoelectric Generator Using Scalable Synthesis of Bi 2 Se 3 Nanoflakes.

Environmental heat-to-electric energy conversion presents a promising solution for powering sensors in wearable and portable devices. However, the availability of near-room temperature thermoelectric (TE) materials is highly limited, posing a significant challenge in this field. Bi 2 Se 3 , as a room-temperature TE material, has attracted much attention. Here, we demonstrate a large-scale synthesis of Bi 2 Se 3 nanoflakes used for the microflexible TE generator. A high-performance micro-TE generator module, utilizing a flexible printed circuit, has been designed and fabricated through the process of screen printing. The TE generator configuration comprises five pairs of PN TE legs. The p-type TE leg utilizes commercially available Sb 2 Te 3 powder, while the n-type TE leg employs Bi 2 Se 3 nanoflakes synthesized in this study. For comparative purposes, we also incorporate commercially available Bi 2 Se 3 powder as an alternative n-type TE leg. The optimal performance of the single-layer microflexible TE generator, employing Bi 2 Se 3 nanoflakes as the active material, is achieved when operating at a temperature differential of 109.5 K, the open-circuit voltage ( V OC ) is 0.11 V, the short circuit current ( I SC ) is 0.34 mA, and the maximum output power ( P MAX ) is 9.5 μW, much higher than the generator consisting of commercial Bi 2 Se 3 powder, which is expected to provide an energy supply for flexible electronic devices.