Direct Current Treatment Tuning Crystallinity Leading to High-Performance p-Type Sb₂Te₃ Flexible Thin Films

With the development of wearable electronics, inorganic flexible thin films (f-TFs) with high thermoelectric performance have attracted increasing research interest. To further enhance the thermoelectric performance of p-type inorganic Sb₂Te₃-based f-TFs, we employed direct current treatment to tune the crystallinity by rationally tuning the direct current treatment time. Correspondingly, a high electrical conductivity of >845 S cm^-1 and a moderate Seebeck coefficient of >110 μV K^-1 within the entire measurement temperature range have been simultaneously achieved. Consequently, a high power factor of 12.84 μW cm^-1 K^-2 at 423 K has been realized in the as-prepared p-type Sb₂Te₃ f-TF treated by a direct current of 5 A for 4 min. A flexible thermoelectric device has been further assembled to demonstrate the power-generating capacity. This study indicates that the direct current treatment is an effective method to improve the thermoelectric performance of Sb₂Te₃ f-TFs.