The Clash of Mechanical and Electrical Size-Effects in ZnO Nanowires and a Double Power Law Approach to Elastic Strain Engineering of Piezoelectric and Piezotronic Devices

The piezoelectric performance of ultra-strength ZnO nanowires (NWs) depends on the subtle interplay between electrical and mechanical size-effects. "Size-dependent" modeling of compressed NWs illustrates why experimentally observed mechanical stiffening can indeed collide with electrical size-effects when the size shrinks, thereby lowering the actual piezoelectric function from bulk estimates. "Smaller" is not necessarily "better" in nanotechnology.