OPTICAL PROPERTIES OF Si-BASED MATERIALS FOR PHOTONIC APPLICATIONS

As the microelectronics industry approaches fundamental limits in terms of processing speed, integrated photonics and optoelectronics are generally regarded as future candidates to increase speeds, primarily in the area of optical interconnects. Unfortunately, as of yet there exists no ideal material for monolithically integrated photonics. Silicon, the dominant material in microelectronics, has an indirect energy band gap and is an inefficient light emitter. Si would, however, be the material of choice for integrated photonics due to the large array of processing tools available for Si and the ability to avoid complex hybrid optoelectronic integration schemes. While bulk Si is not suitable for the development of a Si-based emitter, nanocrystalline Si (nc-Si) does not suffer the same limitations. When taken down to the nanoscale, quantum confinement effects begin to affect the recombination process. Under these circumstances luminescence can be obtained from Si based materials [1].