7×10-8
3×10-6
1×10-5
1×10-9
Figure 3. Color online Current–voltage curves at a forward bias b reverse bias voltage in the
nonetched and etched GaN LEDs.
Figure 5. Color online ESD characteristics of the nonetched and etched GaN LEDs: a forward
voltage measured at 20 mA after application of positive-voltage ESD stress and b forward voltage
measured 20 mA after application of negative-voltage ESD stress.
58% at 20mA
Figure 4. Color online Light output power of etched and nonetched GaN LEDs as a function of
injection current.
Conclusions
Defects were densely concentrated near the surface region ~18 nm of the p-GaN
layer and were effectively removed by using a molten KOH and NaOH solution. The
defect-assisted leakage currents at the forward and reverse bias voltage were
remarkably decreased due to a reduction of DDAP defect, and the light output power of
etched GaN LEDs was significantly improved by 58% at an injection current of 20 mA
due to enhanced injection efficiency. The negative-voltage ESD characteristics of GaN
LEDs were also improved from −0.3 to − 0.9 kV.
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