Emission spectra

Fig. 2. Emission spectra of the original structure, structure A, and structure
B at an injection current of 20 mA.
Electron and Hole concentrations

Fig. 3. Electron and
hole concentrations
of (a) original
structure, (b)
structure A, and (c)
structure B at 20 mA.
The gray areas in
the figure indicate
the locations of QWs
and the horizontal
axis is along the
growth direction.
Radiative recombination rates

Fig. 4. Radiative
recombination
rates of (a) original
structure, (b)
structure A, and (c)
structure B at 20
mA and 120 mA.
CONCLUSION

In order to improve the efficiency droop of blue
InGaN LEDs at high current the structure with
gradually decreased barrier thicknesses from the nlayers to p-layers is proposed to replace the
traditional structure with equal barrier thickness.
REFERENCES

Miao-Chan Tsai, Sheng-Horng Yen, Ying-Chung Lu, and Yen-Kuang Kuo ,
“Numerical Study of Blue InGaN Light-Emitting Diodes With Varied
Barrier Thicknesses”, IEEE PHOTONICS TECHNOLOGY LETTERS,
VOL. 23, NO. 2, JANUARY 15, 2011