Exploring new near-room-temperature thermoelectric materials is significant for replacing current high-cost Bi₂Te₃. This study highlights the potential of Ag₂Se for wearable thermoelectric electronics, addressing the trade-off between performance and flexibility. A record-high ZT of 1.27 at 363 K is achieved in Ag₂Se-based thin films with 3.2 at.% Te doping on Se sites, realized by a new concept of doping-induced orientation engineering. We reveal that Te-doping enhances film uniformity and (00l)-orientation and in turn carrier mobility by reducing the (00l) formation energy, confirmed by solid computational and experimental evidence. The doping simultaneously widens the bandgap, resulting in improved Seebeck coefficients and high power factors, and introduces Te_Se point defects to effectively reduce the lattice thermal conductivity. A protective organic-polymer-based composite layer enhances film flexibility, and a rationally designed flexible thermoelectric device achieves an output power density of 1.5 mW cm⁻² for wearable power generation under a 20 K temperature difference.

Flexible Bi₂Te₃‐based thermoelectric devices can function as power generators for powering wearable electronics or chip‐sensors for internet‐of‐things. However, the unsatisfied performance of n‐type Bi₂Te₃ flexible thin films significantly limits their wide application. In this study, a novel thermal diffusion method is employed to fabricate n‐type Te‐embedded Bi₂Te₃ flexible thin films on flexible polyimide substrates, where Te embeddings can be achieved by tuning the thermal diffusion temperature and correspondingly result in an energy filtering effect at the Bi₂Te₃/Te interfaces. The energy filtering effect can lead to a high Seebeck coefficient ≈160 µV K⁻¹ as well as high carrier mobility of ≈200 cm² V⁻¹ s⁻¹ at room‐temperature. Consequently, an ultrahigh room‐temperature power factor of 14.65 µW cm⁻¹ K⁻² can be observed in the Te‐embedded Bi₂Te₃ flexible thin films prepared at the diffusion temperature of 623 K. A thermoelectric sensor is also assembled through integrating the n‐type Bi₂Te₃ flexible thin films with p‐type Sb₂Te₃ counterparts, which can fast reflect finger‐touch status and demonstrate the applicability of as‐prepared Te‐embedded Bi₂Te₃ flexible thin films. This study indicates that the thermal diffusion method is an effective way to fabricate high‐performance and applicable flexible Te‐embedded Bi₂Te₃‐based thin films.

Lead-free double perovskites have been considered as a potential environmentally friendly photovoltaic material for substituting the hybrid lead halide perovskites due to their high stability and nontoxicity. Here, lead-free double perovskite Cs₂AgBiBr₆ films are initially fabricated by single-source evaporation deposition under high vacuum condition. X-ray diffraction and scanning electron microscopy characterization show that the high crystallinity, flat, and pinhole-free double perovskite Cs₂AgBiBr₆ films were obtained after post-annealing at 300 °C for 15 min. By changing the annealing temperature, annealing time, and film thickness, perovskite Cs₂AgBiBr₆ solar cells with planar heterojunction structure of FTO/TiO₂/Cs₂AgBiBr₆/Spiro-OMeTAD/Ag achieve an encouraging power conversion efficiency of 0.70%. Our preliminary work opens a feasible approach for preparing high-quality double perovskite Cs₂AgBiBr₆ films wielding considerable potential for photovoltaic application.

Ag₂Se shows significant potential for near-room-temperature thermoelectric applications, but its performance and device design are still evolving. In this work, we design a novel flexible Ag₂Se thin-film-based thermoelectric device with optimized electrode materials and structure, achieving a high output power density of over 65 W m⁻² and a normalized power density up to 3.68 μW cm⁻² K⁻² at a temperature difference of 42 K. By fine-tuning vapor selenization time, we strengthen the (013) orientation and carrier mobility of Ag₂Se films, reducing excessive Ag interstitials and achieving a power factor of over 29 μW cm⁻¹ K⁻² at 393 K. A protective layer boosts flexibility of the thin film, retaining 90% performance after 1000 bends at 60°. Coupled with p-type Sb₂Te₃ thin films and rational simulations, the device shows rapid human motion response and precise servo motor control, highlighting the potential of high-performance Ag₂Se thin films in advanced applications.