DESIGN OF NOVEL NANOCRYSTALLINE COMPOSITE-MATERIALS BY MEANS OF PLASMA CVD

We discuss two examples of the application of non-isothermal plasma CV D for the design of novel nanocrystalline/amorphous composite material s. It is shown that the electronic and mechanical properties of the ma terials undergo dramatic change when the crystallite size decreases be low 10 nm where the localization phenomena of charge carriers and phon ons commence: The probability of the phonon assisted radiative recombi nation of the carriers increases resulting in an efficient photolumine scence from nanocrystalline silicon. The mechanical strength of nc-MeN (x)/a-Si3N4 composites increases far above the values of the single co mponents. In both cases, a small crystallite size of less than or equa l to 2 nm, sharp interfaces free of dangling and weak bonds and an app ropriate thickness of the amorphous matrix are needed. So far, only pl asma CVD appears to be able to meet these stringent requirements.