Porous A3B5 compounds

Single crystalline p-type GaSb was made porous by anodic etching in a hydrofluoric acid solution. The morphology, chemical composition and photoluminescence (PL) of the porous layer were investigated. It has been shown that the porous layer consists of Sb2O3, Ga2O3 and GaSb submicron grains formed during electrochemical etching of GaSb. On the basis of the anodic etching mechanism, it was assumed that the dispersed GaSb nanoscale crystallites are embedded in a transparent oxide matrix. The porous layer exhibited red photoluminescence (PL) at 670–740 nm. The observed short-wavelength PL of the porous samples prepared from GaSb, a narrow band gap semiconductor, is explained by the quantum size effect in the GaSb nanocrystals.