According tomedia reports, compared with incandescent lamps, LED bulbs are known for producing large amounts of light using relatively little electricity. But a thin layer of nanoparticles can make them perform better, according to a new study. A typical LED diode consists of a light-emitting LED chip surrounded by a transparent protective dome housing/lens. Although most of the light produced by the chip passes directly through the housing, some of it is reflected back inside.
Unfortunately, reflected light is wasted because it does not enter the diode environment to provide illumination. In addition, it increases the temperature inside the diode, causing the chip to degrade faster — meaning that the LED will not last as long as other lighting methods.
To find a solution to this problem, scientists at Imperial College London and the Indian Institute of Technology recently developed a computer model in which a transparent layer of cheap metal nanoparticles is added between the LED chip and its shell.
These particles act a bit like a microlens mesh, which changes the angle at which light comes into contact with the shell material. As a result, more than 20% of light can pass through instead of being reflected back. This means that the same charge can release more light, plus the LED temperature should be lower, so the life will be longer.
The current plan is to use this technology to produce prototype diodes so that variables such as nanoparticle material, size, shape and spacing can be tested and adjusted.
Dr Debabrata Sikdar of IIT Guwahati, who co-authored the study paper, said: “Although there have been proposals for improvements to the enclosure before, most of these will make LEDs more bulky or difficult to manufacture, reducing the economic impact of the improvements. We believe that based on basic theory and our detailed, balanced optimization analysis, our innovations can be introduced into existing manufacturing processes with little disruption or volume increase. “
The study has been published in Light: Science and Applications.