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The performance of LEDs with Ga-doped ZnO (Ga:ZnO) and Sn-doped In2O3 (ITO) current-spreading layers (CSLs) has been evaluated at high injection current densities. LEDs with electron beam-hydrothermally deposited Ga:ZnO transparent CSLs showed improved performance compared to electron beam deposited ITO at all current densities. External quantum efficiency and wall plug efficiency were both higher for blue emitting LEDs with ZnO. Luminous efficacy increased greatly for the ZnO-based CSL with a peak value of 113 lm/W compared to 82 lm/W for the ITO-based CSL, a 37% improvement.
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High-power LEDs using Ga-doped ZnO current-spreading layers