Wavelength tuning in the purple wavelengths using strain-controlled AlxGa1-xN/GaN disk-in-wire structures

AlxGa1-xN/GaN disk-in-wire polar nanostructures were fabricated, and their optical properties were studied. Wavelength tuning was observed by locally controlling the strain in each nanopillar via its diameter. The measured wavelength shift was in an excellent agreement with a one-dimensional strain relaxation model considering only the elastic and piezoelectric properties of the material. The inhomogeneous broadening decreases and internal quantum efficiency increases with a decreasing nanopillar diameter. The potential extension of strain-induced wavelength tuning across ultraviolet through near infrared was also discussed.