Relating plasma processing, surface morphology, and electronic properties of nanomaterials

Current approaches for analysis of the interrelations among plasma processing, morphological characteristics, electronic and optical properties of nano-structured materials are reviewed briefly. Practical implementation of these approaches is demonstrated for the cases of the plasma-assisted formation of silicon-germanium (Si1-x Ge-x, 0 <= x <= 1.0) nano-structures on Si substrates with different crystalline orientations. Both numerical simulations and experimental studies on the effects of plasma parameters, germanium concentration, boron doping, crystalline orientations of the substrate on low-temperature photoluminescence (PL) of the Si1-xGex structures are considered. Different mechanisms of Si1-xGex morphology formation (e. g. traditional Stranski-Krastanov route as well as new approaches like cluster fluxes created in the plasmas) are compared; the latter ones are more flexible and exhibit wider range of the potential applications. Furthermore, effects of morphological characteristics and phonon confinement as well as energetic characteristics of the optic and acoustic phonons on the PL and electronic parameters of the experimentally studied nano-structures are analysed within the generalized Skettrup model and 'displaced oscillator' approximation.