Cathodoluminescence spectroscopy and Kelvin probe work function correlation of native point defect distributions with piezoelectric voltage in strained ZnO microwires

Direct nanoscale cathodoluminescence and Kelvin probe voltage correlation of native point defects in ZnO microwires with their tip piezovoltages show that they contain electrically charged defects which redistribute both laterally and longitudinally on a nanoscale under applied mechanical strain, setting up electric fields that strongly affect microwire piezoelectric tip voltages. The nanoscale distribution and increased densities of these native defects increase piezovoltage and tip power, of general use for piezoelectric applications including transducers and energy harvesting such as biomedical devices. The dependence of these distributions on specific defect donor vs acceptor nature opens avenues for nanowire growth methods, which can increase nanowire power generation.