화학공학소재연구정보센터
Thin Solid Films, Vol.519, No.24, 8480-8484, 2011
Growth, structure and luminescence properties of multilayer Si/beta-FeSi2NCs/Si/.../Si nanoheterostructures
Multilayer structures (up to 15 layers) with beta-FeSi2 nanocrystallites (NCs) buried in silicon crystalline lattice were grown by successive repetition of reactive deposition epitaxy (RDE) or solid phase epitaxy (SPE) of thin iron film on Si(100) or Si(111) substrates and silicon molecular beam epitaxy (MBE) (100-200 nm). Cross-section high resolution transmission electron microscopy (HR TEM) images and ex situ optical and Raman spectroscopy data prove that NCs formed in silicon matrix have the structure and optical properties of beta-FeSi2. The growth conditions provide no dislocations in silicon lattice were found in the course of TEM analysis. Two types of NCs depth distribution were observed: (i) layered that corresponds to iron RDE and (ii) uniform that occurs in the case of iron SPE. The uniform NCs distribution points out the fact that during a growth process NCs moves up to the surface. In spite of small nanocrystallites size (5-50 nm) and their distribution in silicon cap layers the significant photoluminescence (PL) signal at 0.8 eV was observed for all grown samples. (C) 2011 Elsevier B. V. All rights reserved.