Enhanced light output of AIGalnP light emitting diodes using an indium-zinc oxide transparent conduction layer and electroplated metal substrate

The use of indium-zinc oxide (IZO) as a transparent conduction layer (TCL) for electroplated nickel metal substrate AIGalnP light-emitting diodes with a 300 × 300 μm² chip size was investigated with regard to both fabrication and effectiveness in improving light extraction efficiency. A metal system consisting of AuGe/Au was deposited to form ohmic contact dots for the n⁺-GaAs layer, and then an IZO film was deposited to serve as a TCL. Compared with conventional light emitting diodes (LEDs) with GaAs substrates, the proposed LEDs show an increase in light output power (i.e., δL _op/L_op) by 116.7% at 20 mA and 168.9% at 100 mA.