Anisotropic emission wavelength distribution of semipolar InGaN quantum wells on symmetric convex lens-shaped GaN microstructures

We fabricated InGaN quantum wells (QWs) on convex lens-shaped GaN microstructures formed on semipolar (1¯1¯22¯) GaN substrates. Despite the centrosymmetric lens-like shapes, the overgrown InGaN QWs exhibit an anisotropic emission wavelength distribution. This behavior is distinct from the concentric wavelength distribution found in microlens QWs on the polar (0001) plane. The anisotropic distribution is mainly attributed to the In composition variations, which are influenced by the asymmetry of the (1¯1¯22¯) crystallographic plane. The obtained results demonstrate that the (1¯1¯22¯) microlens QWs serve as multi-wavelength light emitters and allow us to investigate unstable planes around the (1¯1¯22¯) plane, which have remained unexplored.