Preparation of porous glass films using phase separation phenomenon and growth behavior of phase-separated structure

We report the preparation of porous glass films on transparent conductive oxide-coated glass substrates using the phase separation phenomena and the growth behavior of the phase-separated structure. We confirmed that the etched glass films are composed of microscale pores, a three-dimensional porous framework of SiO 2 -rich phase with widths of about 40–300 nm, and a thin surface layer of about 40–90 nm thick. The SiO 2 -rich phase grew by diffusion-dominated growth and then viscous flow-dominated growth.