Yellow and orange sources (LED & LD) result from the controlled annealing of phosphide material systems with a dielectric cap.
About
"The LED light bulb is destined to consign incandescents and fluorescents to the history books. That’s because this lighting source has much to recommend it – it is efficient, long lasting, and hits full brightness in an instant – and its sales are accelerating as prices plummet."
"But the LED might not have the final say in the rise of solid-state lighting. In time, it could be superseded by white-light sources formed by mixing the output of diode lasers emitting at different wavelengths. Attractions of this laser-based technology are the promise of even higher efficacies, a superior colour quality and light-based communication rates that are an order of magnitude higher than those that could be produced by LEDs."
