Question

In order to increase the efficiency of a p-n junction LED, what different architecture can be used and how is the increased efficiency achieved?

Answer 1

LED (Light Emitting Diode) emits the energy more in the visible light spectrum as compared to conventional lighting technologies (flourescent, incandescent ...). This reduces the loss of energy consumed to emit IR, UV spectrum of light, making them more efficient.

Another reason is that LED technology (semiconductor) does not depend on heating a metal etc. to emit light. The incandescent technology for eg. uses a lot of energy for heating the tungsten filament and dissipating this heat. This leads to more efficient conversion of electrical energy to light.

You may also ask, that then why does LED lighting technology have large heat sinks for heat dissipation? This is because the semiconductor technology is also not 100% efficient and it some energy loss happens in the chip as heat. This heat needs to be dissipated quickly using large aluminium heat sinks to prevent damage to the semiconductor chip (diode).