LED bulbs currently available in the market emit high levels of blue light, which has been associated with sleep disturbances and eye problems. A group of researchers from the Department of Chemistry, University of Houston has now created a prototype LED bulb that reduces the blue component instead of concealing it, while also preserving the natural appearance of colors under sunlight. The research, published in the journal ACS Applied Materials & Interfaces, developed a prototype LED that reduces blue light emissions.
The drawbacks of conventional LED bulbs
As the world moves towards energy-efficient solutions, light-emitting diode (LED) bulbs have become a popular replacement for traditional incandescent lights. These bulbs boast low energy consumption, long lifespans, and quick activation times. However, conventional LED bulbs emit a significant amount of blue light, which has been associated with eye problems and sleep disturbances.
Blue light and its impact on health
Blue light emissions from LED bulbs have raised concerns due to their potential impact on health. Constant exposure to blue-tinted lights has been linked to cataract formation, and using these lights in the evening can interfere with the production of sleep-inducing hormones like melatonin, leading to insomnia and fatigue. Previous attempts to create a warmer white LED bulb for nighttime use involved adding red-emitting phosphors, but this merely masked the blue hue without eliminating it.
A new approach to LED design
Researchers Jakoah Brgoch and Shruti Hariyani from the Department of Chemistry, University of Houston have developed a prototype LED that reduces the blue component instead of merely masking it, while also ensuring colours appear as they do in natural sunlight. The scientists synthesised a new luminescent crystalline phosphor containing europium ((Na1.92Eu0.04)MgPO4F) as a proof of concept. Thermal stability tests showed that the phosphor’s emission colour remained consistent between room temperature and the higher operating temperature (301 F) of commercial LED-based lighting. In long-term moisture experiments, the compound demonstrated no change in colour or light intensity.
The prototype LED and its promising results
The researchers fabricated a prototype device by combining a violet-light LED with a silicone cap containing their luminescent blue compound, red-emitting phosphors, and green-emitting phosphors. This prototype produced a warm, bright white light while minimising the intensity across blue wavelengths, unlike commercial LED light bulbs. The optical properties of this prototype revealed that it could render the colours of objects almost as well as natural sunlight, making it suitable for indoor lighting.
The incorporation of this new LED technology in custom neon signs has garnered public interest, as it offers a healthier lighting option without sacrificing visual appeal. However, the researchers acknowledge that further work is needed before the prototype is ready for everyday use. If successful, this innovation could lead to a new generation of LED bulbs that offer improved health benefits by reducing blue light exposure, without compromising on energy efficiency and performance.