Transparent-substrate (Al/sub x/Ga/sub 1-x/)/sub 0.5/In/sub 0.5/P light-emitting diodes with thin active regions

We describe record performance (both external quantum efficiency and luminous efficiency) for cubic-shaped light emitting diodes (LEDs) emitting in the yellow-to-red portion of the visible spectrum. Amber (peak wavelength of 590 nm) and red (630 nm) transparent-substrate (TS) (Al/sub x/Ga/sub 1-x/)/sub 0.5/In/sub 0.5/P/GaP wafer-bonded LEDs are demonstrated with luminous efficiencies exceeding 50 lm/W. These devices exhibit a 1.4/spl times/ improvement over the previous state-of-the-art TS AlGaInP LEDs.