China 
Africa 
Explore chapters and articles related to this topic
Lighting
Published in Dorin O. Neacşu, Automotive Power Systems, 2020
LED color is determined by the energy required for electrons to cross the band gap of the semiconductor and this depends on the semiconductor used: Indium gallium nitride (InGaN): blue, green, and ultraviolet high-brightness LEDs;Aluminum gallium indium phosphide (AlGaInP): yellow, orange, and red high-brightness LEDs;Aluminum gallium arsenide (AlGaAs): red and infrared LEDs;Gallium phosphide (GaP): yellow and green LEDs.
Ingan-Based Solar Cells
Published in Farid Medjdoub, Krzysztof Iniewski, Gallium Nitride (GaN), 2017
However, to achieve the target efficiencies higher than 50%, this VHESC design needs a sub-module including a bandgap of 2.4 eV. In this frame, indium gallium nitride (InGaN) material system is one of the most promising material to provide such a wide bandgaps of 2.4 eV or greater.
Augmenting the internal quantum efficiency of GaN-based green light-emitting diodes by sandwiching active region with p-AlGaN layers
Published in Journal of Modern Optics, 2020
Muhammad Usman, Abdur-Rehman Anwar, Munaza Munsif, Shahzeb Malik, Noor Ul Islam, Tariq Jamil
In solid-state lighting, Indium Gallium Nitride (InGaN)-based light-emitting diodes (LEDs) has gained attention from over the last two decades [1,2]. The improvement in the efficiency of green InGaN-based LEDs is still needed for the complete replacement of conventional lighting/display sources with LEDs [3,4]. The key hindrance to the development of green InGaN-based LEDs is strong piezoelectric polarization induced by lattice misalignment [5,6]. Besides the lattice misalignment, other issues are also involved in the degradation of optoelectronic characteristics. Among them, the most dominant challenge is the improvement of internal quantum efficiency (IQE) [7]. IQE is the ratio of radiative recombination of electron-hole pairs to total recombination (radiative and non-radiative) [8]. Due to the lattice misalignment of alternately stacked layers (InGaN/GaN), the chances of radiative recombination are reduced. Another major problem i.e. quantum confined stark effect (QCSE) also arises due to the lattice misalignment [9]. Some of the following mechanisms have also been reported causing degradation of IQE i.e. Auger recombination (non-radiative recombination) [10,11], asymmetric properties of carriers (electron/hole) [12], leakage of carriers from the active region [13], trapping of carriers due to existence of defects which is favourable for non-radiative mechanisms [14,15], and piezoelectric field due to lattice mismatch of InGaN/GaN layer [16,17]. All the above-mentioned issues are exacerbated in green InGaN-based LEDs due to the high composition of indium [18,19]. To address these issues, various approaches have also been reported. Some of the following strategies such as replacement of electron blocking layer (EBL) with graded EBL [4,20,21], improvement of hole injection as well as uniform distribution of carriers in the active region by inserting simultaneously graded quantum barrier (QB) and EBL [22], the enhancement of IQE at high current density by removing EBL which is attributed to the good injection of holes [23], inserting AlGaInN EBL in MQW structure for the compensation of polarization field at QB/EBL interface region [24–26], engineered QWs [27–29], GaN/AlGaN MQW LEDs have also been proposed with AlGaN being used as QB [30] and some other notable approaches [31,32]. Nevertheless, further effective strategies are needed especially for green GaN-based LEDs because the degradation of IQE at high current density is markedly high. In this study, we propose a possible solution in which 1st GaN-QB, on n-side, is replaced with p-Al0.05Ga0.95N QB and conventional EBL is replaced with graded EBL, simultaneously. The peak IQE of proposed structure is enhanced as well as its droop ratio is reduced at high current density as compared to their conventional structure.