A perspective perception on the applications of light‐emitting diodes

Abstract

Light-emitting diodes (LEDs) continue to penetrate the global market; their pervasiveness clearly being felt in such diverse fields as technological, socio-economic and commercial interests. The multi-billion dollar LED market is shared by various segments, including office and household lighting, street lighting, the automobile industry, traffic signals, backlighting for hand-held devices, indoor and outdoor signs and indicators, medicine, communication systems, crop cultivation using artificial light and many more. The technological development of LEDs has undergone many phases in different parts of the world. From the early discovery of luminescence to the invention of highly efficient organic LEDs, researchers have worked with the prime purpose of improving the performance of luminaires. The need to infuse the market with more efficient and cheaper products has been prevalent from the start. LEDs are a result of this uncontrolled desire of researchers to develop superior products that would displace existing products in the market. To understand what led to the current prominence of LEDs, we give a brief historical overview of the field followed by a thorough discussion of the positive features of LEDs. This work includes the basic requirements, advantages and disadvantages of LEDs in a variety of applications. A brief description of the diverse applications of LED in fields such as lighting, indicators and displays, farming, medicine and communication is given. Considerable importance is placed on discussing the possible difficulties that must be overcome before using LEDs in commercial applications.

Plant Responses to Extended Photosynthetically Active Radiation (EPAR)

“…Recently, LED technology, by having many inherit merits, has gained broad and growing acceptance in the field of lighting and has attracted much attention in indoor plant cultivation. 64 Any bands of light may have a distinct effect on plant physiology both when applied alone or in combination with others. As an effect on photosynthetic pigments of plants, i.e.…”

Catadioptric freeform optical system design for LED off-axis road illumination applications

“…With emerging development of light emitting diode (LED) technologies, LEDs have been revolutionizing almost every aspect of modern life due to their incomparable advantages over traditional light sources, such as long life-time, high energy efficacy, friendliness to environment, good color rendering, and so on [1][2][3][4][5][6]. Undoubtedly there exist increasing needs for LED lighting in the field of road illumination.…”

Orange light‐emitting Ca3Mg3(PO4)4:Sm3+ phosphors

“…[1] Although the commercially available WLEDs offer a long lifetime, high efficiency, eco-friendliness, etc., they fail to achieve a higher color rendering due to the lack of a red component in the overall blending of different color phosphors. [1] Although the commercially available WLEDs offer a long lifetime, high efficiency, eco-friendliness, etc., they fail to achieve a higher color rendering due to the lack of a red component in the overall blending of different color phosphors.…”

“…LED, orange emission, phosphate, phosphor 1 | INTRODUCTION LED-based lighting has geared up to replace the existing inefficient lighting systems. [1] Although the commercially available WLEDs offer a long lifetime, high efficiency, eco-friendliness, etc., they fail to achieve a higher color rendering due to the lack of a red component in the overall blending of different color phosphors. Eu 3+ -doped phosphors have been considered as excellent red-emitting phosphors, but the inclusion of expensive Eu ions does not make these phosphors viable for consideration as low cost lighting.…”

“…[1] Although the commercially available WLEDs offer a long lifetime, high efficiency, eco-friendliness, etc., they fail to achieve a higher color rendering due to the lack of a red component in the overall blending of different color phosphors. The phase formation and morphology of the prepared phosphors were analysed by X-ray diffraction studies and scanning electron microscopy.…”