Methods of reducing the power consumption of a microprocessor system, comprising a microprocessor and memory connected by a bus, are provided which involve optimising a program stored in the memory by rescheduling after linking, swapping equivalent instructions, or swapping the operands of commutative operations. The organic functional layer comprises a first, a second, and a third matrix material, wherein the first matrix material has a larger band gap than the second and the third matrix materials. Consistent recording quality is thus obtained despite changes in the recording position on the optical disc or changes in recording conditions.