Light emitting Diode technology is not a latest concept in science and technology, it was in the frame since 1960s. But its presence and effects increases from 1994 when shuji Nikamura of Nichia Corporation was demonstrated in 1994. They provide efficient, effective and energy saving lighting devices available as compared to traditional fluorescent, incandescent light bulbs and tubes. The wavelength of emitted light and its colors largely depends on energy band diagram.
In Silicon or germanium diodes, electrons and holes recombines through non-radiative transition, not producing optical emission, because they indirect band gap materials. The materials used for LED contains adirect band gap along with energies in respect to near-infrared, ultraviolet or visible light.
These development in early 1990's in LED's gave birth to efficient and luxury lighting devices like LED Panels and LED Grow lights. They not only save energy but also provide effective luxury lightings.