Bi–Sb–Te-based semiconductors possess the best room-temperature thermoelectric performance, but are restricted for application in the wearable field because of their inherent brittleness, rigidity, and nonscalable manufacturing techniques. Therefore, how to obtain thermoelectric materials with excellent thermoelectric properties and flexibility through the batch production process is a serious challenge. Here, we report the fabrication of flexible p-type thermoelectric Ag-modified Bi0.5Sb1.5Te3 films on flexible substrates using a facile approach. Their optimized power factors are ∼12.4 and ∼14.0 μW cm–1 K–2 at 300 and 420 K, respectively. These high-power factors mainly originate from the optimized carrier transport of the composite system, through which a high level of electrical conductivity is achieved, whereas a remarkably improved Seebeck coefficient is simultaneously obtained. Bending tests demonstrate the excellent flexibility and mechanical durability of the composite films, and their power factors decrease by only about 10% after bending for 650 cycles with a bending radius of 5 mm. A flexible thermoelectric module is designed and constructed using the optimized composite films and displays a power density of ∼1.4 mW cm–2 at a relatively small ΔT of 60 K. This work demonstrates the potential of inorganic thermoelectric materials to be made on flexible/wearable substrates for energy harvesting and management devices.

A flexible TE generator exhibits a high power density of 897.8 μW cm−2 at a relatively small ΔT of 40 K.

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Although YBa2Cu3O72212δ (YBCO) is one of the most promising superconducting materials for power applications, the fabrication of low-cost coated conductors with the high in-field performance remains challenging. Here, we report an efficient mixed-pinning landscape for enhancing the in-field performance of BaTiO3 (BTO)-doped YBCO films by low-energy (60 keV) proton irradiation. The smaller (2–4 nm), weaker but perhaps denser pinning sites have been successfully introduced by irradiation, which can form a mixed-pinning landscape with pre-doped BTO precipitates (5–15 nm), leading to the increased vortex pinning. In this case, the critical current density (J c) of YBCO films increases significantly, especially at low temperature and high magnetic field, and it increases three times near 6 T at 20 K when the irradiation dose is 1 × 1015 proton cm−2. Additionally, the c-axis length (c-parameter) of YBCO increases with the increase of irradiation dose, which indicates the decreasing oxygen content due to the excessive irradiation, thereby the reduction in critical transition temperature (T c). Employing low irradiation energy is beneficial for protons to stop inside YBCO film and thereby induces higher density defects when applying low doses. This fabrication technique is a practicable post-production solution to improve the in-field performance of nanoparticle-doped YBCO films.

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Bismuth selenide materials (Bi2Se3) have the high-performance around room temperature, demonstrating the potential in thermoelectric applications. Presently, most vacuum preparation techniques used to fabricate the film materials, such as