Oji Holdings Corporation has established the fabrication technology of patterned sapphire substrates (PSS) for LEDs which improves the performance of front luminance of LEDs by more than double compared to that of LEDs with non-structured sapphire substrate, by applying the technique of precise coating with fine particles.
Compared to a conventional flat sapphire substrate with a 385nm wavelength, the front luminance of a nano-dot patterned PSS is more than double, and total luminous flux is 1.8x. What does this mean? To attain the same brightness:
- The same LEDs can be driven at 50% power.
- The number LEDs can be halved.
Of course brightness can be more than doubled using the same number of nano-dot PSS LEDs. New displays using nano-dot PSS LEDs will sport roughly double the brightness or double the battery life or somewhere in between.
There has been much talk of Apple’s development agreement with GT Advanced, a manufacturer of sapphire substrates. Many conjecture sapphire will be used as a cover glass for iPhone, displacing Corning Gorilla Glass. Other usage cases might be to secure direct supplies for camera lens covers, Touch ID covers, and perhaps as a sapphire cover for the much rumored iWatch. Another usage scenario might be for sapphire substrates for LEDs. In this scenario, Apple and GT Advanced would manufacture PSS and supply them to LED manufacturers, which in turn would be used in backlight units that go into displays for iPhones, iPads, MacBooks, iMacs, and monitors.