Triboelectric current generation in InP

Energy harvesting is an area that presents the greatest potential for powering wireless low-energy electronics. Development of semiconductor-based energy harvesting is of interest. Herein we focus on studying two different energy harvesting mechanisms in indium phosphide. Piezoelectric harvesting was checked by bending vertical InP nanowires with conductive atomic force microscope (AFM) probe and simultaneously detecting current passing through the probe. No current pulses were observed that we associate with surface trapping of piezoinduced carriers. Triboelectric generation was studied by creating frictional contact between AFM tip and metal-dielectric-semiconductor (MIS) interface formed by InP layer covered with native oxide. Current peaks of 320 pA amplitude corresponding to the current density around 2.3 kA/m(2) were observed under sliding reciprocating motion of the tip during AFM scanning. Achieved current density was higher than in polymer- and silicon-based triboelectric structures. The open-circuit voltage value exceeded 15 mV and the output electric power was 35 W/m(2).