Optical properties of arrays of Si nanopillars on the (100) surface of crystalline Si

We studied Si nanopillars arrays interesting for potential applications in both photonics and electronics. Two types of the Si nanopillars arrays were investigated. The first type is a regular array (square lattice with the spacing of similar to 270 nm) made up of nanopillars with diameters of 60-70 nm (non-quantum nanopillars). Polarized reflection spectra displaying photonic band gap features and the corresponding photonic band structures were studied. The second type is a non-regular array made up of nanopillars with diameters of 10-20 nm (quantum nanopillars), Enhancement of the optical phonon Raman band, change of selection rules and a low-frequency shift of similar to 0.5 cm(-1) of the band corresponding to the quantum size effect in Si cylinders with average diameter similar to 15 nm were observed for the quantum nanopillars. (C) 2000 Elsevier Science B.V. All rights reserved.