|Special lighting for horticultural applications becomes a high-priority development. (Osram photo)
Phosphors are critical to the future of light-emitting-diode (LED) applications since they can impact LED lighting quality in very fundamental ways. Phosphors can support wide ranges of color lighting. In addition to combining blue LEDs with yellow phosphors to create green shades, many opportunities exist for enhanced color rendering through the use of high-quality red phosphors. Phosphors also enable improved LED efficiency and lower-cost operation. Existing phosphors have provided LEDs with 100 percent greater increases in LED efficacy and 50 to 200 percent declines in price, and new phosphor materials may do even better.
Such beneficial phosphor characteristics can help the growing application of LEDs where they are already gaining market share, such as for general illumination and where performance concerns or consumer perceptions have previously limited the use of LEDs. Aggressive phosphor firms will benefit from these situations not just because they offer enabling technology for LEDs but because they are willing to explore the development of new phosphor materials with improved performance.
Phosphors and LEDs
Advances in phosphors in relation to LEDs can help the growth of LED sales for general illumination applications by modifying the general consumer perception that LEDs provide only dull and cold lighting, a key reason why consumers avoid LEDs for general lighting. According to market research by NanoMarkets, demand is expected to increase for reliable LEDs that can produce warm lighting effects and operate with long lifetimes, and these LEDs will require phosphors that improve color rendering index (CRI) and efficacy. Without improvements enabled by phosphors, white LEDs will remain relatively unattractive to consumers, given their cooler color temperatures, allowing alternative lighting technologies to gain ground.
Phosphor suppliers and academic researchers are intensifying efforts to improve performance and are making progress toward enabling growth in this sector. These suppliers and researchers are going beyond traditional combinations of blue LEDs and yellow phosphors to create white light that is more appealing for increased market growth.
- General Electric is developing manganese-based red emitters with narrow line-width properties. These red emitters can overcome the efficacy limitations of existing broadband red emitters, specially, emission in wavelengths beyond the visible spectrum. New hybrid phosphors can help meet the demand for high-brightness white LEDs. Europium(II)-doped red nitrides combined with yellow-cerium(IV)-doped phosphors are showing great promise in this area.
- Hybrid materials are greatly aiding the development of next-generation LEDs. Hybrid nitride/nitrogen-oxide red/green phosphors offer high reliability and high CRIs, and the production costs for these materials are dropping.
- OSRAM (www.osram.com) is succeeding with various combinations of materials, such as blue LEDs with green phosphors, and combining those with red or amber LEDs. This approach eliminates the need for a phosphor to produce red light, allowing OSRAM to use a green phosphor with high efficacy.
- Ultraviolet (UV) LEDs can be combined with red, green, and blue phosphors to produce white light. Mitsubishi (www.mitsubishielectric.com) has achieved what it claims is the spectrum equivalent to sunlight by using this approach.
Such efforts, if successful and priced appropriately, can help drive the pace at which consumers turn away from compact fluorescent lights (CFLs), halogen lights, and the new breed of high-efficiency luminescent light bulbs and embrace LEDs for general illumination.
LEDs and Television
Phosphors offer an opportunity for LEDs to play more significant market roles in the television market, by improving the quality of the LED lighting in televisions. LED backlighting units (BLUs) for televisions and other high-performance liquid-crystal displays (LCDs) were among the earliest applications for high-performance LEDs. At first, LED BLUs were a distinguishing feature for LCDs, but now they are commonplace in televisions and mobile displays, with the BLU market currently saturated for this application.
|Interiors become more manageable and economical to light. (Osram photo)
In general illumination applications, phosphors offer an opportunity to expand a nascent market for LEDs by making the quality of LED lighting more acceptable. In the television market, phosphors can be the enabling technology to revive a mature market. But if manufacturers can produce a new breed of phosphors, NanoMarkets believes that the availability of these new phosphors could bring new life to the television market. This could happen if phosphor suppliers can create narrower-emission phosphors. Some of the phosphor materials in development for general illumination, especially red emitting phosphors, would also enable growth in the television market. New developments in phosphors could also strengthen the market position for LED-lit LCDs, although suppliers will need to improve light uniformity across the color spectrum to succeed in the LCD space.
High-volume applications for phosphor-enabled LEDs are clearly in areas such as displays and general lighting, but additional revenue opportunities will also emerge in a number of niche markets, and these should not be ignored. For example, new phosphor materials may pave the way for greater acceptance of LEDs in the theatre and studio lighting sector. Consumer perception is critical in the theatre and studio lighting sectors, and new phosphor materials may help pave the way for greater acceptance of LEDs in these sectors. The industry understands the energy and cost-savings potential with LEDs, but lighting designers feel that tungsten lights have an emotional appeal that LEDs lack.
Firms producing phosphor products can contribute to these markets by tailoring the proper products for these business segments. Phosphor solutions that provide precise control of blue, red, and far-red wavelengths may allow the theatre lighting industry to overcome its prejudice against LEDs and lead to increased penetration of LEDs in this sector. Phosphors for this sector must be thermally stable and compatible with theatrical-grade dimming to succeed. In addition, cost is often a critical parameter in the cash-strapped theatre industry. Suppliers of LEDs to this industry will need to emphasize long-term cost savings, such as by eliminating the frequency of light bulb replacements and providing lower electric bills, to increase the use of LEDs in these applications. Reductions in the up-front costs of LED bulbs will also aid their wider adoption in these applications.
New phosphor materials may enable expansion into applications sectors previously off-limits for LEDs, such as in museums. Blue light is absorbed rather than reflected by the yellow and brown colors of parchments, faded textiles, and ancient artifacts, which can cause damage. Innovative phosphor solutions, such as using violet or UV LEDs in combination with red, green, and blue phosphors to create white light, can help increase the use of LEDs within the museum lighting sector.
Some LED manufacturers are making inroads into museum-based applications. For example, OSRAM announced that it will be retrofitting the lighting in the Sistine Chapel with LED-based fixtures in order to highlight the Michelangelo frescoes. LED-based lighting will enable higher luminance levels for iconic artwork, preserving visitors' views of the historically significant work while consuming 60 percent less energy than existing lighting approaches.
In addition to the various applications already mentioned, LEDs offer the potential to support a broad range of diverse fields, with many potential opportunities for firms developing new phosphor materials. The greatest revenue growth is expected to occur in the areas of general illumination, from a market size of about $50 million in 2014 to more than $250 million by 2021. Over that same period, LED phosphor revenues in other sectors are expected to be flat or decreasing. But the increasing use of phosphors in these markets can provide improved color control, better efficacy, and lower cost, clearing the way for innovative firms to reap their share of benefits.
A new report from NanoMarkets provides thorough analysis of the latest opportunities in those LED phosphor markets, building on NanoMarkets' 2012 report. The new study, available by visiting the firm's site at www.click.ipctrack.com, details how the LED phosphor market is evolving in response to the latest developments in both display backlighting and general illumination requirements. The report, which includes assessments of the product/market strategies of the leading firms active in the LED phosphor space, contains granular eight-year forecasts of the LED phosphor shipments in volume and value terms, with breakouts by type of phosphor and type of application.
Contact: NanoMarkets, LC, PO Box 3840, Glen Allen VA 23058 804-938-0030 fax: 804-360-7259 E-mail: firstname.lastname@example.org Web: http://www.nanomarkets.net