Optimization of the Output Efficiency of GaN Nanowire Piezoelectric Nanogenerators by Tuning the Free Carrier Concentration.

Carrier concentration in a piezoelectric semiconductor greatly affects alternating current (AC) piezoelectric nanogenerators (NGs) because of the carrier screening effect on the piezoelectric potential. The output performance of a series of NGs is investigated by tuning the Si dopant concentration in GaN nanowires. The results show a strong carrier screening effect that degrades output performance for high doping concentrations but results in high output power for low doping concentrations. [ABSTRACT FROM AUTHOR]