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     Ladcameo Pilla Bewarse Username: Ladcameo Post Number: 194 Registered: 02-2013 Posted From: 195.59.193.142 Rating: N/A |
mari ee range lo copy aa 1. From the first paragraph in “et al and CNR Rao”: “However, conversion with traditional phosphors results in poor colour rendering due to the relatively weak green and red emission from the respective components of the phosphor mixtures. In addition the phosphors are traditionally prepared in typical grain sizes of tens of micrometres inhibiting the development of advanced devices, where the emitter elements could be comparable to or smaller than the particle size of the phosphors.” From Itskos et al, Nanotechnology (2009) 10.1088/0957-4484/20/27/275207 “However, conversion with traditional phosphors results in poor colour rendering due to the relatively weak green and red emission from the respective components of the phosphor mixtures. In addition, the phosphors are traditionally prepared in typical grain sizes of tens of micrometres. This is a limitation in the development of advanced devices where the emitter elements could be comparable to, or smaller than, the particle size of the phosphors.” 2. Immediately after the previous extract in “et al and CNR Rao”: “Organic semiconductor light-emitting diodes (LEDs) in turn can span the entire visible spectrum and have low-cost potential due to high-throughput manufacturing, offering new prospects for displays and lighting applications. These two semiconductor families have their own special advantages and disadvantages. Especially, inorganic materials exhibit excellent electrical properties but need complex and expensive fabrication techniques to characterise them. Their spectral coverage is also limited, although down-conversion with phosphors allows access to other colours and white-light emission. Comparatively organic semiconductors offer excellent luminescence properties, with a greater variety of emission wavelengths, but exhibit relatively poor electrical behaviour. Combining the desired features of both the families is clearly an attractive proposition.” From Heliotis et al, Advanced Materials (2006): DOI: 10.1002/adma.200501949 “Organic semiconductor light-emitting diodes (LEDs) in turn can span the entire visible spectrum and have low-cost potential due to high-throughput manufacturing, opening attractive prospects for displays and lighting. These two semiconductor families have their own especial advantages and disadvantages. Most notably, GaN structures offer excellent electrical properties but are inherently prone to the complex and expensive fabrication techniques that characterize inorganic semiconductors. Their spectral coverage is also limited, although down-conversion with phosphors allows access to other colors and white-light emission. On the other hand, organic semiconductors offer excellent luminescence properties, with a greater variety of emission wavelengths and significantly higher photoluminescence efficiencies, but exhibit less good electrical behavior. Combining the best attributes of each family would clearly be an attractive proposition.” |