GaN-Substrate LEDs: Introduction nPola
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Seoul Semiconductor’s patented nPola technology increases brightness levels 5 times over existing LEDs. This technology took more than 10 years to develop and is set to revolutionise the LED lighting industry. nPola stands for Numerous polarities and is related to the substrate in which the LED is grown. nPola is grown on a GaN (Gallium nitride) substrate, whereas conventional LEDs use Sapphire or Silicone substrate in which most of the energy is converted to heat instead of light due to a defect caused by lattice mismatch. nPola, however, does not have the lattice mismatch issue like conventional LEDs because the GaN epitaxy has the same crystalline structure as the GaN growth substrate. Furthermore, nPola technology involves the utilization of the one of the nPola non-polar planes in the GaN crystal, either the a-plane or m-plane, whereas traditional LEDs currently utilize the polar c-plane GaN epitaxy on Sapphire or Silicon. nPola LEDs offer reduced electrical resistance, increased electrical efficiency, reduction in colour shift with varying operating current and smaller device size. With nPola, Seoul Semiconductor has already improved the lumen density of LEDs by 5 times over the conventional LEDs based on equivalent die surface area and it expects to further improve this margin to 10 times in future.