Development of efficient and durable sources of white light

Abstract

This review presents a brief history of the development of light sources over the centuries to provide one of the human race's basic needs -light. Recent moves in Europe to encourage the adoption of compact fluorescent lamps as more energy-efficient replacements for incandescent lights, despite certain drawbacks, are described. Rapid strides are now being made in the development of solid-state 'white' lights which are already sufficiently durable and efficient to warrant adoption for both domestic and public lighting purposes. Their basic construction and comparative performance, properties and uses are fully described, together with the many ideas for improving their brightness and durability still further. Solid-state devices offer additional savings compared with those which should be achieved under the EU's targeted replacement of incandescent lights by 2012, and later one can expect such devices to compete with high-pressure sodium luminaires for street lighting.

Changing colours: now you see them, now you don’t

“…Light emitting polymers will play an important role in the future as a branch of organic lightemitting diodes, as energy-saving sources of white light. Many manufacturers are vigorously exploring their technical and commercial potential, but at present their durability and cost need improving [96].…”

Photoluminescence and structural properties of Ca3Y(VO4)3:RE3+ (=Sm3+, Ho3+ and Tm3+) powder phosphors for tri-colors

“…Since its picture quality depends mainly on the type of phosphors employed in a display, the selection of typical phosphors is utmost important. Another interesting area of phosphor development is fluorescent and solid-state lighting as back light for non-emissive displays [3][4][5].…”

Organic emitters for solid state lighting

“…For organic and inorganic light emitting diodes (OLEDs and LEDs) the luminous power efficiency, defined as the output light power from a device per electrical power input, has respectively reached and overcome the value of 100 lm W −1 [1,2], which is comparable to that of fluorescent lamps (65-100 lm W −1 ) and much higher than that of incandescent light bulbs (15 lm W −1 ) [3,4].…”