InGaN blue light-emitting diodes with ZnO nucleation layers prepared by the sol–gel method

InGaN blue light-emitting diodes (LEDs) were fabricated on a sapphire substrate with a ZnO nucleation layer that was deposited by the sol–gel method. Typical current–voltage ( I – V ) characteristics of the InGaN blue LEDs with a ZnO nucleation layer have a forward-bias voltage of 3.25 V at an injection current of 20 mA, and reverse currents of 2.33 × 10 −8 and 5.91 × 10 −7 A at reverse biases of 10 and 20 V, respectively. The InGaN blue LEDs have an ideality factor n of 1.27 at a forward bias of 1.8 V. The external quantum efficiency at an injection current of 20 mA was measured to be 12.82%. The light output power reached as high as 23.2 mW at a forward current of 100 mA.