LED lamps will replace light bulbs in near future

Seems this can be true. Faiz Rahman who is a nano electronics researcher at Glazgow university states that low-energy bright LED light Bulbs are almost here. As matter of fact LEDs are very energy efficient, but fact is that about 70% of electrical energy is converted to light, and only about 20% of it getting out. The rest of light is trapped inside semiconductor due to high refractive index of LED-air surface.

But as Faiz says by making LEDs to let more light out their brightness can be compared to ordinary light bulbs. How to make this happen? This can be done by making series of holes on the surface of LED. Rahman has already made several LED prototypes where holes on surface are about 200nm in diameter (400 times narrower than human hair) and 100nm deep. As LED chip is about 0.3×0.3mm there is enough space for hundreds of thousands of holes.

This trick with holes actually reduces the LED-air surface refractive index what means less light is reflected back from air to semiconductor. Rahman refers this as “photonic crystal” – an optical nano structure that manipulates light. Such technology allows extracting about 80% of generated light(for times more than current LEDs does).

Further question is how to create these structures fast. As now using electron beam it took about 30 minutes to prepare few LEDs. But in mass production we are talking about millions and more. Thay have a solution for that also. A simple nano-lithography can solve this. First a stamp with nanoscale protrusions (where holes will be) has to be made. Then stamp has to be pressed down on to wafer of LED chips this way deforming imprint resist and then etching will form the holes.

Rahman’s first LED devices are intended for use in backlights within LCD TVs, replacing cold cathode tubes and helping make thin TVs even thinner. As for those bright, money-saving LED lightbulbs for the home, there may not be a long wait. “You should be able to buy them in two to three years’ time,” Rahman says.” [guardian]

3 Comments:

  1. dear sir,

    i hav need ur LEDlights in small. ur produt of very useful in our life good thinking of mind work. my address
    g.premkumar
    lig 1265 tnhb
    rk road hosur 635109

  2. You can’t buy led lights here haha.

  3. I’m reading this post in 2016. It’s amazing this technique conquered the world in just a few years.

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