evidot^® LEDS - Improving LED Lighting

Limitation of Traditional LEDs

Light Emitting Diodes (LEDs) produce light through the use of a p-n semiconductor junction. Essentially, LEDs utilize a semiconductor material to convert electrical power into light. Traditional LEDs are inherently efficient and long lasting. However, LEDs suffer some restrictions due to the limitations of traditional semiconductors. One notable restriction is the color of light (wavelength) produced by the LED. This color is controlled by the semiconductor material and is set by nature. This limitation is due to the fixed bandgap of traditional semiconductors and this restriction effectively limits the introduction of LEDs into a number of applications.

LEDs and Phosphors

Due to the limitations of traditional LEDs, it is necessary to use phosphors to convert the light emitted by the LED to produce white LEDs and some specialty colors. Phosphors are typically rare earth compounds. The most common phosphor used in the production of white LEDs is yttrium aluminum garnet (YAG), which is deposited onto a blue InGaN LED. The phosphor absorbs the blue light and emits light of a different wavelength determined primarily by the phosphor compound. Phosphors are useful for a number of applications but they also have limitations. Primarily, the emission color of phosphors is limited by nature and difficult to alter. Because the emission color is limited by nature, phosphors can produce only a restricted set of colors. This limits the usefulness and efficiency of LEDs in a number of applications.

LED Comparison Graph Quantum Dot LED Diagram

evidot^® LEDS - A More Versatile Generation of LEDs

evidot LEDs are different. evidot LEDs utilize quantum dot semiconductor nanocrystals to convert shorter wavelength light to longer wavelength light. Unlike phosphors however, the emission color of quantum dots is tunable and the absorption of quantum dots is extremely broad. This allows for complete control of the LED emission color. evidot LEDs represent a marked increase in performance over standard LEDs because they can be tuned to emit at any wavelength, overcoming many of the shortcomings of traditional LEDs. The unique properties of the quantum dot are due to their very small size (2-10nm). At these sizes, quantum mechanics allow semiconductor materials to take on new characteristics, including that of a tunable bandgap controlled by the addition of subtraction of only a few atoms. By controlling the quantum dot's size Evident can control their color, allowing us to overcome nature's limitations. For more information about quantum dots, click here to view our quantum dot tutorials.

More Color Possibilities

evidot LEDs, enabled by quantum dots, can emit at almost any color. This provides more color options, including unique colors such as pink and purple. Click here to view details about our specialty color LEDs.

More White Light Possibilities

evidot LEDs provide new colors to solid state lighting. LEDs enabled by quantum dots provide us with full spectrum control. Our white LEDs range in color temperatures from 2250K to 8000K with very high CRI. Click here to learn more about our white LEDs. Click here to view details about our specialty color LEDs.