Hybrid graphene-NiW nanofiber transparent electrodes for all-nanofiber-based pressure sensor

Alloying technique as an ancient and practical instrument has been a diverse fabricator for desirable properties of materials. Herein, utilizing the alloying engineering, we have developed a two-step process for hybrid graphene-NiW nanofibers (Gr-NiW NFs) transparent electrodes. Further analysis reveals that alloying NiW NFs significantly improve their mechanical performance, reducing the growth temperature of graphene down to ~ 700 °C or below, which is far less than that of ~ 1000 °C for graphene grown on Cu or Pt. More importantly, such Gr-NiW network has exhibited excellent transmittance in a broad wavelength and remarkable conductivity, which, in turn, could be tailored by the growth temperature and the W content. A high transmittance (84.2% at 550 nm) and low sheet resistance (125.4 Ohm/square) were observed at Ni NFs with 5 wt% W. The combination of excellent conductivity, high transparency and mechanical tunability makes it a promising candidate for wearable electronics and optoelectronics. Finally, an all-nanofiber-based pressure sensor on sandwiched Gr-NiW/P(VDF-TrFE)/Gr-NiW NFs was demonstrated, with high sensitivity (0.61 mV kPa⁻¹) and excellent operation stability. This work offers deep insights into the development of transparent graphene-based electrodes via alloy engineering.