Fabricating high-quality GaN-based nanobelts by strain-controlled cracking of thin solid films for application in piezotronics

► ZnO/r-sapphire substrates were used for growing InGaN/GaN bilayer films by MOCVD. ► ZnO template was removed by lateral wet chemical etching to crack the bilayer film. ► The film cracks propagate along the c-axis of InGaN/GaN lying in the surface plane. ► InGaN/GaN-nanobelt arrays of large lengths and areas are fabricated by this method. ► Such nanobelts have great potentials for applications in piezotronics.