GaN nanowires for piezoelectric generators

We demonstrate the high potential of GaN nanowires (NWs) to convert mechanical energy into electric energy. Using an atomic force microscope equipped with a Resiscope module, an average output voltage of -74 mV and a maximum of -443 mV +/- 2% per NW were measured. This latter value is the highest reported so far for GaN NWs. By considering these output signals, we have estimated an average and a maximum power density generated by one layer of GaN NWs of the order of 5.9 mW/cm(2) and 130 mW/cm(2), respectively. These results offer promising prospects for the use of GaN NWs for high-efficiency ultracompact piezogenerators. ((c) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)