Optical properties of Si-doped Al(sub)xGa(sub)1-xN/Al(sub)yGa(sub)1-yN (x=0.24-0.53, y=0.11) Multi-quantum-well structures

摘要

We demonstrate strong ultraviolet (UV) (280-330 nm) photoluminescence (PL) emission from multi-quantum-well (MQW) structures consisting of AlGaN active layers fabricated by metalorganic chemical-vapor-deposition (MOCVD). Si-doping is shown to be very effective in order to enhance the PL emission of AlGaN QWs. We found that the optimum values of well thickness and Si-doping concentration of Al sub x Ga SUB 1-Xn/Al sub y Ga sub 1-yN (x=0.24-0.53, y=0.11) MQW structure for efficient emission were approximately 3nm and 2x10 sup 19 cm sup -3, respectively. In addition, the PL intensities of AlGaN, GaN and InGaN quantum well structures are compared. We have found that the PL emission at 77K from a Al sub 0.53 Ga sub 0.47N/Al sub 0.11 Ga sub 0.89 N MQW is strong as that of InGaN QWs.