A truncated-inverted-pyramid (TIP) chip geometry provides substantial improvement in light extraction efficiency over conventional AlGaInP/GaP chips of the same active junction area (∼0.25 mm2). The TIP geometry decreases the mean photon path-length within the crystal, and thus reduces the effects of internal loss mechanisms. By combining this improved device geometry with high-efficiency multiwell active layers, record-level performance for visible-spectrum light-emitting diodes is achieved. Peak efficiencies exceeding 100 lm/W are demonstrated (100 mA dc, 300 K) for orange-emitting (λp∼610 nm) devices, with a peak luminous flux of 60 lumens (350 mA dc, 300 K). In the red wavelength regime (λp∼650 nm), peak external quantum efficiencies of 55% and 60.9% are measured under direct current and pulsed operation, respectively (100 mA, 300 K). © 1999 American Institute of Physics.
CITATION STYLE
Krames, M. R., Ochiai-Holcomb, M., Höfler, G. E., Carter-Coman, C., Chen, E. I., Tan, I. H., … Collins, D. (1999). High-power truncated-inverted-pyramid (AlxGa1-x)0.5In0.5P/GaP light-emitting diodes exhibiting >50% external quantum efficiency. Applied Physics Letters, 75(16), 2365–2367. https://doi.org/10.1063/1.125016
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