Influence of Si-doping on the characteristics of InGaN-GaN multiple quantum-well blue light emitting diodes

On the Effect of Step-Doped Quantum Barriers in InGaN/GaN Light Emitting Diodes

“…In Device I, only polarization induced charges are shown in Fig. 6(b), since there are no Si dopants in the quantum barriers and the simulated electron sheet charge density in the fifth quantum well is around 1.4 10 cm , which is negligible compared to the polarization charge density that is in the order of 10 cm [29]. Thus we obtain the macroscopic electric field in (1) at both "A" and "B" sites, respectively, which explains the field symmetry for Device I in Fig.…”

“…Finally Ti/Au (30 nm/150 nm) was deposited on the n-GaN layer as the n-electrode. between the electron and hole wave functions [29], thus enhancing the radiative recombination rates. Nevertheless, in the low current regime (4.8 mA mA), Device II performs worse than Device I.…”

“…3 presents the electroluminescence (EL) for the studied devices, where the emission intensity is the strongest for Device III and the weakest for Device I. Meanwhile, Devices II and III show a shorter peak emission wavelength compared to Device I, which is attributed to the slightly relieved QCSE by Si-doped quantum barriers [29]. However, the less pronounced blue-shift for all the three devices as the injection current increases is caused by the junction heating effect [38].…”

“…The strain induced spatial separation of electron-hole wave functions can further be completely eliminated in the non-polar quantum wells and increased radiative recombination rates can thus be obtained [27], [28]. It has also been shown that the material quality and the device performance can be substantially improved by introducing Si doping in quantum barriers [29]- [31]. However, Si-doped barriers or even Si-delta-doped barriers usually have a setback from holes blocking [32], [33], which leads to a high local hole accumulation.…”

Influence of Si‐doping on the characteristics of InGaGdN/GaN MQWs grown by MBE

“…In order to fabricate spintronic devices which have longer emission wavelengths, it is important to improve the quality of the InGaGdN/GaN interface. Wu and Cho et al have reported that Si-doping in the barrier of the InGaN/GaN MQW improved the crytalline quality [3,4]. Hence, we tried Si-doping into the barrier and grow the InGaGdN/GaN:Si MQW structures to confirm the effect of Si-doping.…”