SWCNTs/Ag₂Se film with superior bending resistance and enhanced thermoelectric performance via in situ compositing

High power factor contributes high power generation output while high bending resistance extends the service life in flexible thermoelectric device. Here, we report an in situ grown 10 mol% single-walled carbon nanotubes (SWCNTs) and Ag_2+ySe (named as 10 mol% SWCNTs/Ag_2+ySe) film, which shows a high power factor of 19.36 μWcm⁻¹ K⁻² at 300 K and excellent bending resistance. Such a high power factor is attributed to the enhanced carrier concentration and enlarged effective mass, induced by the additional interstitial Ag in the in situ grown Ag₂Se on SWCNTs. Moreover, the 10 mol% SWCNTs/Ag_2+ySe film can remain 95 % of the initial electrical conductivity after 1000 bending cycles at the radius of 5 mm, indicating an excellent bending resistance. In addition, this film was assembled into a flexible thermoelectric power generator, which can achieve an output power of 0.72 μW and an open-circuit voltage of 18.17 mV at a temperature difference of 30 K. This study indicates that in situ compositing Ag₂Se on SWCNTs can realize the increased thermoelectric performance and bending resistance, which drives the application of Ag₂Se-based flexible films.