Porous Quaternary Al0.1In0.1Ga0.8N Film Formation via Photoelectrochemical Etching in HF:C2H5OH Electrolyte

Pore formation in AlInGaN films using photoelectrochemical etching in different volume ratios of hydrofluoric acid:ethanol solution (1:1, 1:2, 1:3, and 1:4) has been investigated structurally, morphologically, and optically. A significant increase in root mean square roughness and photoluminescence intensity in AlInGaN film etched in 1:1 solution has yielded the highest pore density and the largest average pore size in the film. Moreover, the acquisition of the lowest total dislocation density as well as the largest in-plane biaxial stress relaxation in the film suggested potential use of the porous film as a template to grow subsequent layers for development of light-emitting diodes.