Time-dependent degradation of Pt/ZnO nanoneedle rectifying contact based piezoelectric nanogenerator

A piezoelectric nanogenerator based on the platinum rectifying contact on ZnO nanoneedle arrays (NNA) has been successfully fabricated on silicon substrate by using the thermal evaporation deposition technique. It is demonstrated that the rectifying platinum contact on ZnO NNA can efficiently convert nanoscale mechanical energy into electrical energy by exploiting the piezoelectric and semiconducting properties of ZnO. The effect of key parameters such as scanning speed, force on scanning tip, and tip abrasion on the nanogenerator has been studied along with long-time stability of the piezoelectric nanogenerator. The study reveals that the nanogenerator output degrades with time primarily due to degradation of the rectifying contact with time and abrasion of the tip caused by repeated scanning. The results of the study are expected to provide quantitative ideas about the long-time stability of ZnO NN based nanogenerators. (C) 2011 American Institute of Physics. [doi:10.1063/1.3553862]