Breakthrough for LED Efficiency
Scientists at Glasgow University have discovered a way to increase the efficiency of LED bulbs which has brought closer the possibility of LED bulbs being used for home illumination.
Dr Faiz Rahman, a nanoelectronics researcher at the University has explained how he and his team have been able to release much of the light that has previously been reflected back inside the LED. Although LEDs have a very high ratio of energy converted to light, only 20% is emitted outside. This is partly due to the fact many LEDs are made using gallium nitride which is not an ideal optical material, in that it is transparent and has a very high refractive index.
Rahman’s method for unleashing the untapped potential of LEDs sounds ridiculously simple. By creating a series of 200nm holes spaced 300nm apart on the surface of the LED he has been able to increase the amount of light released to 80%, which represents a big step towards making the technology viable for lighting our homes. The holes alter the refractive index of the semiconductor and reduces the level of internal reflection.
The exact details of his method are still a secret, but it seems clear that the rapid development of LED technology is continuing apace, and further advances will be just around the corner.
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