Open AccessLuminescence and optical constant of ZnSe/SiO2 composite thin films
Author(s) -
Haiqing Jiang,
Xi Yao,
Jun Chen,
Minqiang Wang
Publication year - 2006
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.55.2084
Subject(s) - photoluminescence , materials science , thin film , luminescence , lattice constant , scanning electron microscope , composite number , exciton , analytical chemistry (journal) , crystal (programming language) , optics , diffraction , optoelectronics , nanotechnology , composite material , chemistry , condensed matter physics , physics , chromatography , computer science , programming language
The ZnSe/SiO2 composite thin films were prepared by sol-gel process a nd in-situ growth technique. X-ray diffraction results showed that the phase str ucture of ZnSe particles embedded in ZnSe/SiO2 composite thin films i s the sphalerite (cubic ZnS). X-ray fluorescence results revealed that the molar ratio ofZn/Se is about 1∶1.01—1∶1.19. Scanning electron microscopy results r evealed that the size of ZnSe crystal particles is about 400nm, while some parti cles are less than 100nm in size. The dependence of ellipsometric angle Ψ, Δ w ith wavelength λ of ZnSe/SiO2 composite thin films was investigated with spectroscopic ellipsometers. The optical constant, thickness, porosity and the concentration of ZnSe in ZnSe/SiO2 composite thin films were fitt ed according to Maxwell-Garnett effective medium theory. The photoluminescence p roperties of ZnSe/SiO2 composite thin films were investigated with fl uorescence spectrometer. The photoluminescence results indicated that the emissi on peak at 487nm under 395nm excitation corresponds to the band-to-band emission of sphalerite ZnSe crystal. The strong free exciton emission and other emission peaks correlated with ZnSe lattice defect were also observed.