Effect of Barrier Thickness and Barrier Doping on the Properties of InGaN/GaN Multiple‐Quantum‐Well Structure Light Emitting Diode

Abstract

Optical and electrical properties of InGaN/GaN multi-quantum-well (MQW) structure light-emitting diodes (LED) are systematically studied as a function of barrier thickness and Si doping of barriers. The emission energy of photoluminescence (PL) and electroluminescence (EL) of MQWLEDs decrease with barrier thickness increased, but with Si doping of barriers decreased. The electrical characteristics of MQW-LEDs strongly depend on barrier thickness and Si-doped content in barriers. With increasing barrier thickness, forward voltages of MQW-LEDs dramatically reduce as well as the barriers are increasingly doped with Si. Reverse currents of MQW-LEDs measured at reverse bias 6 V present a similar behavior that Ir increase with increasing barrier thickness as well as increasing Si doped content in barriers. The experimental results imply an optimized quality of MQW-LED fabrication by an appropriate combination of barrier thickness and carrier concentration.Introduction III-V nitride semiconductor materials are attracting much attention in optical and electrical application for research filed and commercial purpose. Especially, the InGaN/GaN MQWs are widely used as the active layer in violet, blue, green LED and LD applications. Many studies on the growth of the InGaN/GaN MQWs to improve the optical properties have been explored [1][2][3][4][5][6][7]. These studies have investigated the effect of barrier doping, well and barrier thickness playing a crucial role on the optical of the MQWs. But there have been few reports on the effect of barrier doping level and barrier thickness on electrical properties of the MQWs. In this study, we report the influence of electronic carrier concentration in Si-doped barrier and the thickness of barrier on the optical and electrical properties of InGaN/GaN MQWLEDs.

Effect of AlGaN Si-Doped Barrier Layer on Optical Properties of Ultraviolet Light-Emitting Diodes

“…The decrease in forward voltage in LEDs with increasing Si doping concentration is attributed to the lower series resistance. 10) In order to investigate the carrier transport within LED devices to improve light output power, simulations of the charge distribution and recombination rate were performed using SiLENSe software. 11) A modified drift-diffusion model with corrections and direct flight mechanisms, spontaneous and piezoelectric polarization fields, and a doping-and field-dependent mobility model specific to nitrides have been applied.…”

InGaN∕GaN Multiple-Quantum-Well LEDs with Si-Doped Barriers

“…The smaller forward voltage observed from the LED with Si-doped barriers should be attributed to the lower series resistance of the barriers. 23 As a result, the operation voltage in the vertical direction will become smaller. Such a result also indicates that one can improve the electrical properties of nitride-based LED by doping Si into GaN barrier layers.…”