Jegenyes, N.; Morassi, M.; Chrétien, P.; Travers, L.; Lu, L.; Julien, F.H.; Tchernycheva, M.; Houzé, F.; Gogneau, N. High Piezoelectric Conversion Properties of Axial InGaN/GaN Nanowires. Nanomaterials2018, 8, 367.
Jegenyes, N.; Morassi, M.; Chrétien, P.; Travers, L.; Lu, L.; Julien, F.H.; Tchernycheva, M.; Houzé, F.; Gogneau, N. High Piezoelectric Conversion Properties of Axial InGaN/GaN Nanowires. Nanomaterials 2018, 8, 367.
We demonstrate for the first time efficient mechanical to electrical energy conversion using InGaN/GaN nanowires (NWs). Using an atomic force microscope equipped with a modified Resiscope module, we analyse the piezoelectric energy generation of GaN NWs and demonstrate an important enhancement when integrating in their volume a thick In-rich InGaN insertion. The piezoelectric response of InGaN/GaN NWs can be tuned as a function of the InGaN insertion thickness and position in the NW volume. The energy harvesting is favoured by the presence of a PtSi/GaN Schottky diode which allows to efficiently collect the piezo-charges generated by InGaN/GaN NWs. Average output voltages up to 330 ± 70 mV and a maximum value of 470 mV per NW has been measured for nanostructures integrating 70 nm-thick InGaN insertion capped with a thin GaN top layer. This latter value establishes an increase of about 35% of the piezo-conversion capacity in comparison with binary p-doped GaN NWs. By considering these output signals, we estimate a maximum power density generated by one layer of dense InGaN/GaN-based NW of about 3.3 W/cm2. These results settle the new state-of-the-art for piezo-generation from GaN-based NWs and offer a promising perspective for extending the performances of the piezoelectric sources.
III-N Nanowires; Piezoelectric generation; Atomic force microscope; Piezo-generators; Energy harvesting
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