Light-emitting diodes (LED) have attracted people’s attention due to their special features such as low power consumption and high durability. At the same time, their low-carbon, energy-saving, and environmental protection features, make LED frequently applied in areas such as display, photos, and optical communications. With the acceleration of the development of solid-state photo technology, LED has become the most promising environmentally friendly lighting source to be used widely. However, due to the physical properties of GaN-based materials, the low light extraction rate severely limits the sustainable development of LEDs. As a result, how to improve the light extraction efficiency (LEE) of LEDs is one of the most important research in the field of solid-state lighting. One of the reasons for the relatively low LEE comes from the phenomenon of total internal reflection inside the chip, resulting in photon absorption and loss of capacitance, which greatly reduces the LEE of GaN-based LEDs. This paper mainly summarizes the methods of patterning the titanium layer, patterning/roughening Indium-tin Oxide (ITO) transparent electrode layer, patterning sapphire substrate, special-shaped chip, back shadow, photonic crystal, and stealth cutting to capture high LEE of the LEDs.

Shi Cao, Sheng Huang, Yinghan Wu. Study on light extraction of nitride LED. Academic Journal of Materials & Chemistry (2023) Vol. 4, Issue 6: 43-47. https://doi.org/10.25236/AJMC.2023.040608.

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