1. Experimental Details 1 Fig. 1. Schematic diagram of the investigated LED layer structure. In the present work, the Mg doping width of the LT p-GaN interlayer is varied. 2.5 nm thick In0.28Ga0.72N QWs 15 nm thick GaN QBs 3 periods InGaN/GaN superlattice 1 nm

2. Results And Discussion(1/5) 2 Fig. 2. RT PL spectra and XRD rocking curves of InGaN/GaN green LED with and without a LT u-GaN interlayer. ∼ 50% higher InGaN AB FWHM37.8 nm31.5 nm

3. 3 Fig. 3. SIMS depth profiles of the LED samples. Results And Discussion(2/5)

4. 4 Fig. 4. FWHMs of the EL spectra for the LED samples as a function of the injection current. ( △ λ is EL FWHM broadening in the range of 100mA.) Results And Discussion(3/5) 20mAABCDE 波長 (nm) 515.4521.3519.9517.6513.2

5. 5 Fig. 5. (a) Light output power and (b) relative EQE for the LED samples (A-E) as a function of the injection current. Results And Discussion(4/5) 100mAABCDE droop78%69%62%65%71%

6. 6 Fig. 6. Simulation result of (a) hole concentration and (b) electron current density distribution in the vertical direction when the injection current is 100 mA. (Zero is the interface between the first GaN barrier and n-GaN). Results And Discussion(5/5) 100mA

7. Conclusion The optimized hole doping depth for achieving an excellent optical performance was found to be ∼ 30 nm,where the electron leakage current is sufficiently suppressed and the QW degradation by Mg diffusion is minimized. The experimental results are also supported by numerical simulation. The proposed LED structure with optimized Mg doping depth is expected to be advantageous for achieving high brightness and high efficiency of InGaN green LEDs.

8. T. Mukai, M. Yamada, and S. Nakamura, “Characteristics of InGaNbased UV/blue/green/amber/red light-emitting diodes,” Jpn. J. Appl. Phys., vol. 38, no. 7A, pp. 3976–3981, Apr. 1999. H.-Y. Ryu et al., “Efficiency and electron leakage characteristics in GaN-based light-emitting diodes without AlGaN electron-blocking-layer structures,” IEEE Photon. Technol. Lett., vol. 23, no. 24, pp. 1866–1868, Dec. 15, 2011. P- 型氮化鎵歐姆接觸製作研究 - 國立中央大學, 光電科學研究所, 研究生 - 黃宏基 References