HIGH-BRIGHTNESS INGAN/ALGAN DOUBLE-HETEROSTRUCTURE BLUE-GREEN-LIGHT-EMITTING DIODES

High-brightness InGaN/AlGaN double-heterostructure blue-green-light- emitting diodes with a luminous intensity of 2 cd were fabricated by increasing an indium mole fraction of the InGaN active layer up to 0.23. Both Zn and Si were codoped into the InGaN active layer to afford relatively stronger luminescence. The blue-green emission intensity of room-temperature photoluminescence became maximum when the electron carrier concentration of the InGaN active layer was around 1×1019 cm-3. Donor-acceptor pair recombination is a dominant emission mechanism of the InGaN active layer. The external quantum efficiency was as high as 2.4% at a forward current of 20 mA at room temperature. The peak wavelength and the full width at half-maximum of the electroluminescence were 500 and 80 nm, respectively. © 1994 American Institute of Physics.