An Irish company has been lucky enough to achieve a milestone record this week in the field of LEDs. InfiniLED, based in County Cork, Ireland, has developed a record-breaking light output density of more than 300W/cm2 for a commercially available LED device. The firm's newest device is capable of generating nearly 1mW of light from a single 20µm pixel at a 405nm wavelength. The highly energy-efficient MicroLED product is currently being aimed towards applications including life sciences, consumer electronics and original equipment manufacturer based equipment.
The MicroLED offers the wavelength flexibility, drive characteristics and simplicity of an LED plus the power and collimated beam of a semiconductor laser to boost light output. A parabolic reflector is etched into the semiconductor material during the fabrication process, placing this key optical component directly at the site of light generation and at an optimal position for control of the light. By directing all the generated light through a single surface of the semiconductor, it can be efficiently collected and utilized more effectively.
The device has the flexibility to be fabricated as a single pixel, large clusters of pixels or as addressable arrays where each pixel is switchable independently. The single pixels can be used to produce high intensity, collimated light over a small area or to produce light at very low currents down to a few nanoamps.
These MicroLEDS can be clustered together in unison to produce even higher light density and collimated emission over a wider area based on application needs. MicroLEDs are also available as addressable arrays of pixels, where collimation from each pixel results in high packing densities and minimal crosstalk between the devices. In addition, the high current densities achievable and low capacitance allows the MicroLEDs to be switched at very high speeds, which is another major benefit.
Interestingly enough, packaging is responsible for 40-60 percent of the total cost of an LED device. Thus, packaging is the primary area needed to be addressed for cost reduction, which is necessary for the industry to reach its full potential, especially amid the enormous opportunity in energy-efficient general lighting. More industry standardization is essential for generating the desired cost reduction for wide-scale adoption. Semiconductor companies with retrofitted equipment have entered into this fray to enable this transition, but the results have been fixed thus far.
There are a wide range of LED package designs for various applications, including but not limited to: single or multiple chips, low- and mid-power plastic leaded chip carrier, ceramic-based high-power LEDs, smaller or larger arrays, system-on-chip and chip-on-board, which ultimately act as an impediment to associated economies of scale. Companies such as InfiniLED will be able to capitalize better on technology breakthroughs once the LED industry streamlines its packaging supply chain and standardizes its designs to lower costs for large-scale commercialization and growth.