Minor magnesium doping in P-type layer of InGaN/GaN MQW LED to enhance electrical and optical properties

In this study, the LED samples were grown by metalorganic chemical vapor deposition (MOCVD) on 430 mum-thick c-plan sapphire substrates. The layer sequence consisted of a 25.0 nm GaN nucleation layer followed by a 2.0 mum-thick undoped GaN buffer layer, a 2.0 mum-thick Si-doped GaN conduction layer, a active region composed of five 2.5 nm-thick In_0.23Ga_0.77N QWs separated by 12.0 nm-thick GaN barriers, followed by 15 pairs of Mg-doped AlGaN/GaN superlattice structure consisting of 3.0 nm AlGaN layers, and 3.0 nm GaN layers, a 30.0 nm-thick Mg-doped GaN cap layer. Finally, a 10.0 nm Mg-doped GaN contact layer was grown on the top of LED.