AlGaN/AlGaN double-heterojunction ultraviolet light-emitting diodes grown by metal organic chemical vapour deposition

Light emitting diodes using an Al_xGa_1-yNiAl _yGa_1-yN double-heterojunction have been demonstrated with an ultraviolet emission peak at λ=321 nm with a linewidth of 7.7 nm. The devices were grown by metal organic chemical vapour deposition on c-plane sapphire substrates. The active region is composed of a single layer of Al_xGa_1-xN (x=0.23) and the cladding layers are p-type and n-type Al_yGa_1-y N (y=0.45). The light output from the diodes was measured through the sapphire substrate in a `p-side down´ configuration. At a current of 35 mA DC, an output power of ~39 nW was measured without any coatings on the device