InGaN/GaN-Based Energy-Efficient Blue LEDs for Illumination

Light-emitting diodes (LEDs) are narrow-band light sources based on semiconductor material, with wavelengths ranging from the infrared to the ultraviolet. The material that enabled the development of blue LEDs was Gallium Nitride. Gallium Nitride is a semiconductor of the III-V class. GaN can be doped, with silicon to n-type and with magnesium to p-type. The development of efficient blue LEDs also required the production of GaN based alloys with different compositions and their integration into multilayer structures such as heterojunctions and quantum wells. For GaN based light-emitting diodes is reviewed. There are two broad developments in GaN-based LED technology: Ist, the key breakthroughs that enabled the development of GaN-based devices on foreign substrates like sapphire , and, IInd, a new wave of devices benefiting from developments in GaN substrate manufacturing, which has GaN based LEDs with unprecedented performance characteristics that portend a disruptive shift in LED output power density and the corresponding cost of generating light. The invention of efficient blue LEDs has led to white light sources for illumination. By coating a blue LED with a phosphor material a portion of the blue light can be converted to yellow, green, and red light. This mixture of colored light will be perceived by humans as white light and can therefore be used for general application.