Optical properties of Pb(Zr,Ti)O[sub 3] thin films on sapphire prepared by metalorganic decomposition process

[[abstract]]Pb(Zr0.52Ti0.48)O3(PZT) thin films were synthesized on a sapphire substrate for application as planar optical waveguide devices using a metalorganic decomposition (MOD) process. Pyrochlore phase, which always forms preferentially when the PZT thin films (~200 nm) are deposited on a sapphire substrate directly, has been effectively suppressed by using a SrTiO3(STO)film (~190 nm) as a buffer layer. The PZT/sapphire thin films have a significantly larger refractive index than the STO/sapphire ones: n PZT=2.2012 and n STO=2.0639 (at 632.8 nm) by prism coupling measurement and n P'ZT=2.215 and n S'TO=2.084 (at 632.8 nm) by optical transmission spectroscopic measurement. The STO layer cannot only serve as buffer layer for enhancing the crystallization kinetics of the subsequently deposited PZT thin films, but can also serve as cladding layer in a ridge-type planar waveguide, which uses PZT thin film as core materials.[[notice]]補正完畢[[journaltype]]國

Dependence of the electrical properties of defective single-walled carbon nanotubes on the vacancy density

[[abstract]]The relationship between the electric properties and the vacancy density in single-walled carbon nanotubes has been investigated from first principles as well as the dependence of the influencing range of a vacancy in the nanotube on the nanotube chirality. Compared with the long-range interaction of the vacancies in a single-walled carbon nanotube with non-zero chiral angle, a much shorter interaction was found between vacancies in a zigzag single-walled carbon nanotube. In this study, we investigated the bandstructure fluctuations caused by the nanotube strain, which depends on both the vacancy density and the tube chirality. These theoretical results provide new insight to understand the relationship between the local deformation of a defective single-walled carbon nanotube and its measurable electronic properties.[[journaltype]]國外[[incitationindex]]SCI[[ispeerreviewed]]Y[[booktype]]紙本[[booktype]]電子版[[countrycodes]]GB