Formation of porous layers on n-GaSb by electrochemical etching

The effect of electrochemical etching of n-type GaSb in aqueous solutions of HCl and HF has been analysed.By anodization in HCl, two different morphologies of porous layers were observed depending on the current density.At low current density (0.5 mA cm -2 ) a macroporous layer is formed with the pores following preferential directions, while at high current density (15 mA cm -2 ) pores of sizes less than 100 nm were observed.Furthermore, a comparison between the luminescence in the porous layer and bulk GaSb is also performed.On the other hand, anodization in HF leads to an electropolishing process and no porosification is obtained.