1. Ru-Chin Tu, Chun-Ju Tun, Shyi-Ming Pan, Chang-Cheng Chuo, J. K. Sheu, Ching-En Tsai, Te-Chung Wang,and Gou-Chung Chi IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 15, NO. 10, OCTOBER 2003 D.J. Sum

2.  Introduction  Experiment  Results and discussion  Conclusion  References

3.  AlGaN cap is generally placed above the MQW to prevent electron overflow from the active region, and to protect the InGaN active region from the subsequent high-temperature growth of p-type layers.

4. Sapphire C face LT-GaN 30nm at550 ℃ Si-doped(n-GaN) MQW 5pair MQW(well2.5nm; barrier 7.5nm); Si doped GaN barrier layer P-GaN Ti/Al Ti/Au 0.2μm TCL 調變： 1. 成長溫度 2. 成長時氣體環境 3. 通 Cp2Mg 流量 30nm Chip Size 300×300μm P-AlGaN 4μm at1050 ℃

5. Fig. 1. Schematic band diagram of the InGaN–GaN MQW active region with (a) the Mg-doped AlGaN EB layer on the last InGaN quantum well and (b) on the last GaN barrier.

7. Fig. 2. RT EL spectra of LEDs 7B (160 mA), 7D (20 mA), and 7F (20 mA). The inset plots the relative output luminous intensity as a function of injection current between 10 and 250 mA for three LEDs.

8. Fig. 3. Forward I–V characteristics of three LEDs. The forward voltage of LED 7B (V = 3.63 V) exceeds that of both LEDs 7D and 7F (V = 3.25 V).

9. Fig. 4. RT EL spectra of LEDs 7D (20 mA), 8B (60 mA), and 9F (20 mA). The inset plots the relative output luminous intensity as a function of injection current between 10 and 250 mA for three LEDs.

10. Fig. 5. Reverse I–V characteristics of three LEDs. The leakage currents of LEDs 7D, 8B, and 9F at a reverse bias of 5V were approximately 6 nA, 3.75 A, and 50 nA, respectively.

11.  The EL intensity of LEDs with LT-grown Mg- doped AlGaN layers was nearly three times larger than that of LEDs with HT-grown AlGaN.  An Mg-doped AlGaN layer in N 2 ambient grown at LT is found to be better than that grown in the H 2 ambient due to the prevention of dissociation and etching of the final InGaN well layer.

12.  Ru-Chin Tu, Chun-Ju Tun, Shyi-Ming Pan, Chang-Cheng Chuo, J. K. Sheu, Ching-En Tsai,Te-Chung Wang,and Gou- Chung Chi “Improvement of Near-Ultraviolet InGaN–GaN Light-Emitting Diodes With an AlGaN Electron-Blocking Layer Grown at Low Temperature” IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 15, NO. 10, OCTOBER 2003

13. Thanks you