Lateral Force Coupling in Piezoelectric GaN Nanorods Grown on Pyramided Si Substrate

How to efficiently harvesting piezoelectric energy is a critical issue for scavenging ambient mechanical motion for driving compact, low-power, multi-functional electronic devices. Herein, by applying a normal force, we report an innovative structure for harvesting piezoelectric energy from bending the obliquely aligned GaN piezoelectric nanorods (NRs) that are integrated with the vertically integrated nanogenerator (VING) by using plasma-assisted molecular beam epitaxy (PA-MBE) technique. Using conductive atomic force microscope (AFM), a remarkable change in the Schottky barrier height (SBH) between the tip and GaN NR is observed upon bending an oblique-aligned GaN NR. This demonstrates that a remarkably enhanced piezoelectric performance of GaN NRs can be achieved by coupling a lateral force.