Triboelectric nanogenerators fabricated with GaN nanowires as a response medium

We discuss the device performance of triboelectric nanogenerators (TENGs) fabricated with GaN nanowires (NWs) as a response medium. The TENGs were fabricated by forming polydimethylsiloxane (PDMS) and a Pt/Cu electrode on the top and bottom of the GaN NW/Si(111) structure, respectively. To evaluate the effect of the PDMS layer on the performances of the TENG, the curing agent ratio in PDMS was varied to 0.05% (TENG1), 0.09% (TENG2) and 0.13% (TENG3). When touching the top surface of the TENG2 with a human finger, the maximum output voltage and power density were measured to be 6 V and 23.83 mW/m2, respectively, which are much higher than those of previous works. These results will be discussed using a theoretical model with vertical and spatial distribution of strain at the interface between the PDMS and GaN NWs.