Effects of polarized-induced doping and graded composition in an advanced multiple quantum well InGaN/GaN UV-LED for enhanced light technology

Abstract

In this paper, a light-emitting diode in the ultra-violet range (UV-LED) with multiple-quantum wells (MQWs) of InGaN/GaN is designed and analyzed through Technology Computer-Aided Design (TCAD) simulations. The polarization effects in III-nitride heterojunction and the effects of graded composition in the electron blocking layer (EBL) are exploited to enhance the performance of the proposed UV-LED. It is observed that the effect of graded composition in the EBL helps to enhance the electrical and optical performance of the LED, thereby enabling the achievement of some promising results. The simulation-based results demonstrated that superior internal efficiency and an inferior leakage current are achieved by using a graded Al composition in the EBL rather than a uniform composition. The reported results also confirm the remarkable improvement of the light output power by 17% at ~100mA when using the graded composition and also show a reduction in series resistance leading to more current. Graded Al composition in the EBL results in the enhancement of electroluminescence spectra (i.e., an increase in the peak of the spectral density)

Polarization Engineered p-Type Electron Blocking Layer Free AlGaN Based UV-LED Using Quantum Barriers with Heart-Shaped Graded Al Composition for Enhanced Luminescence

“…The constant analytical dependence of the anticipated IQE on the radiative current density (j rad ) is a further significant characteristic of the ABC model, as shown in Equation (12).…”

“…Due to the direct tunable band gap, between 3.43 eV and 6.11 eV, AlGaN ternary alloy is quite applicable to the fabrication of optical devices within a wavelength range of ∼200-360 nm [1]. This is suitable for sterilization [2][3][4][5], ultra-violet printing [6,7], bio-medical appliances [8,9], deodorization using a photo catalyst [10,11], dermatology in medicine [12,13], and sensing applications for materials, for example urea [14,15]. However, the internal quantum efficiency (IQE) and light output power (LOP) of UV-LEDs using AlGaN alloys are still low because of several adversities.…”

Optimizing performance and energy consumption in GaN(n)/In x Ga 1- x N/GaN/AlGaN/GaN(p) light emitting diodes by quantum-well number and mole fraction

“…The band gap (Eg) values for barrier and well layers have been adjusted. For indium nitride (InN) and gallium nitride (GaN) the band gap values are 0.7 and 3.42 eV, respectively, at room temperature [47,48]. The band gaps cover the spectrum from visible range up to far ultraviolet.…”

“…From the band structure, it is evident that the quantum well is created when there is a band discontinuity in the heterojunction [52]. The GaN barriers have a band gap value of 3.42 eV [47] and the wells have adjustable value depending on the In mole fraction x. For the present study, 0.16 is used for indium in InxGa1-xN quantum well [53].…”

The role of indium composition in InxGa1−xN prestrained layer towards optical characteristics of EBL free GaN/InGaN nanowire LEDs for enhanced luminescence

“…5 III-nitride materials are capable of manufacturing lasers and LEDs, 6,7 but it is still difficult to get high efficiency GaN/InGaN LED. The strong piezoelectric polarization (PZ), along the c-plane direction, induced by high lattice mismatch within GaN and InGaN layers causes the quantum-confined Stark effect (QCSE) 8 which eventually causes reduction of device's efficiency (EQE). 9,10 However the Stark effect is not preferable as it causes notable spatial separation of the carrier wave functions.…”