[en] Self-assembled AlGaN nanowall networks have been epitaxially grown on c-plane sapphire by laser molecular beam epitaxy (LMBE) without employing any additional process. Field emission scanning electron microscopy study reveals that a porous nanowall network is grown uniformly over a large area. The width of AlGaN nanowalls is ranged typically in 20-30 nm. It is found that these self assembled nanowalls are highly oriented in c-direction. Room temperature photoluminescence measurement exhibited a near band edge luminescence at about 3.51 eV for the grown AlGaN nanowall network. (author)