Enhancement of Structural and Optical Properties of Porous In0.27Ga0.73N Thin Film Synthesized Using Electrochemical Etching Technique

This paper presents the growth conditions of In0.27Ga0.73N/Si(111) thin film with thickness of 110 nm prepared using plasma-assisted molecular beam epitaxy technique. Indium mole fraction of 0.27 was calculated using X-ray diffraction and Vegard’s law. Some ridges on the film were observed on the as- grown surface morphology. Furthermore, porous In0.27Ga0.73N structure was synthesized using UV- assisted electrochemical etching technique with various current densities. Formed pores were dissimilar in terms of shape and size because of changes in the etching current density. Crystallite size and the strain inside the film were calculated for both as-grown and porous In0.27Ga0.73N. The result shows that both crystallite size and compressive strain decreased with increasing current density. A slight blue shift of porous In0.27Ga0.73N regarding the wavelength of the as-grown film was observed at 554 and 553.1 nm by using photoluminescence measurements. Finally, a Raman phonon mode of A1(LO) at 625.6 cm-1 of the as-grown film was observed. However, a shift towards higher frequency was monitored in the porous In0.27Ga0.73N film.