TABLE I. Summary of the structural parameters of the shallow QWs in three samples extracted from the XRD (004) ω/2θ scan measurements and the corresponding performances of LED devices.
Results and Discussion
FIG. 2. (a) Current-voltage characteristics of Sample A, B, and C. (b) Inte-grated EL intensity of Sample A, B, and C as a function of injection current.
turn-on voltage
Sample A 2.70 V
Sample B 2.75 V
Sample C 3.05 V
@ ( 1 mA )
EL intensities
Sample A 1.94
Sample B 1.70
Sample C 1.23
Under 20 mA (40 A/cm2)
14%57%
lighting efficiency (light output/electric power input)
FIG. 3. Reciprocal space mapping around GaN asymmetric (10.5) diffrac-tion of (a) Sample A and (b) Sample C.
ε xx
GaN on sapphire -0.23%
Sample A -1.92%
Sample B -1.94%
Sample C -1.98%
InGaN QWs with In% = 16%