Elastic buckling of AlN ribbons on elastomeric substrate

Abstract

For optoelectronic applications requiring unconventional substrates, use of flexible forms of semiconductors may be inevitable. We have fabricated a flexible form of single crystalline AlN ribbons with periodic and wavelike structures on an elastomeric substrate. Single crystalline AlN films were grown on Si (111) substrate using high vacuum unbalanced magnetron sputtering. Crystallinity of the AlN films was confirmed with x-ray diffraction and pole figure. The AlN ribbons were transferred to a prestrained (3.1%) elastomeric substrate and the resulting “wavy” ribbons on the substrate were flexible up to 30% strain without any crack formation on the surface. As the film thickness changed from 300 to 900 nm, the periods of the waves varied from 95 to 277 μm, which were within a 10% error of the calculated values. When we applied more than 30% strain, mechanical instability, such as the failure of AlN ribbons due to the cracks on the surface and the merged ribbons, was observed.

Pre-patterned ZnO nanoribbons on soft substrates for stretchable energy harvesting applications

“…Piezoelectric materials, such as lead zirconate titanate (PZT), [1][2][3][4] barium titanate (BaTiO 3 ), 5,6 aluminum nitride (AlN), 7 and zinc oxide (ZnO) [8][9][10][11] have been utilized to convert mechanical vibration energy into electrical energy for portable or self-powered electronics, among many other applications, such as solar cells. 12,13 Specifically, "piezoelectric nanogenerator," 8 first introduced in 2006, has boomed the applications of nano-scale piezoelectric materials for energy harvesting.…”

“…14 In order to accommodate the development of consumer electronics, piezoelectric nanogenerators are expected to be able to integrate with wearable or stretchable devices and different approaches with success to some extent, such as limited stretchability, have been attempted. 2,3,5,7,8 The deformability, i.e., bendability and stretchability, is realized by bonding buckled piezoelectric materials on top of soft materials. There are two limitations among existing work, namely, energy harvesting only at the high frequency domain and stretchability.…”

Random analysis on controlled buckling structure for energy harvesting

“…8 It has been found that superior power generation is realized by using bistable buckled beams. 9 Buckled piezoelectric beams (such as zirconate titanate, 10 aluminum nitride, 11 and zinc oxide 12 ) have also been used for stretchable energy harvesting.…”