Titanium wave-like surface microstructure for multiple reflections in solar cell substrates prepared by an all-solution process

A two-stage all-solution electrochemical process has been developed to etch a wave-like surface microstructure in titanium. In the first stage, anodization creates a porous oxide surface layer. In the second stage, alcoholic-electrolyte electropolishing removes titanium from beneath the oxide to etch the microstructure. Experimental and simulated angle-resolved reflectivity are compared to confirm that multiple reflections occur inside cavities of the microstructure. The target application is solar cell substrates where multiple reflections can significantly increase the device efficiency.