The distance between the needle tip and metal collector was about 10 cm. The resultant nanofibers were dried at 90 C for
1 h.
For the fabrication of nanogenerator, another ITO-coated PET film was attached to cover the upper part of the composite fiber layer so that the final structure becomes the ITO-coated PET film/NKN-P(VDF-TrFE) layer/ITO-coated PET film.