Optimization design of transparent conductive Al-doped ZnO and mechanism for performance-enhancing GaN light emitting diodes

The current crowding effect is one of the key factors that reduce the performance of light emitting diodes (LEDs). The transparent Al-doped ZnO (AZO) film, which was employed as a current spreading layer for a GaN-based blue LED, had been prepared and optimized by adjusting deposition parameters. Experimental results showed an obvious enhancement of the electroluminescence performance of the LEDs by using the highly transparent and low-resistance AZO layer. The mechanisms were discussed on the basis of the optical and electrical characteristics. The ANSYS simulation analysis proved that the optimized AZO layer weakened the current crowding effect in the GaN-based blue LED.