The annealing effect on the spectral and nonlinear optical (NLO) characteristics of ZnO thin films deposited on quartz substrates by sol-gel process is investigated. As the annealing temperature increases from 300–1050 °C, there is a decrease in the band gap, which indicates the changes of the interface of ZnO. ZnO is reported to show two emission bands, an ultraviolet (UV) emission band and another in the green region. The intensity of the UV peak remains the same while the intensity of the visible peak increases with increase in annealing temperature. The role of oxygen in ZnO thin films during the annealing process is important to the change in optical properties. The mechanism of the luminescence suggests that UV luminescence of ZnO thin films is related to the transition from conduction band edge to valence band, and green luminescence is caused by the transition from deep donor level to valence band due to oxygen vacancies. The NLO response of these samples is studied using nanosecond laser pulses at off-resonance wavelengths. The nonlinear absorption coefficient increases from 2.9×10−6 to 1.0×10−4 m/W when the annealing temperature is increased from 300 to 1050 °C, mainly due to the enhancement of interfacial state and exciton oscillator strength. The third order optical susceptibility χ(3) increases with increase in annealing temperature (T) within the range of our investigations. In the weak confinement regime, T2.4 dependence of χ(3) is obtained for ZnO thin films. The role of annealing temperature on the optical limiting response is also studied.

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Structure and properties of W O 3 -doped Pb 0.97 La 0.03 ( Zr 0.52 Ti 0.48 ) O 3 ferroelectric thin films prepared by a sol-gel process J. Appl. Phys. 98, 034104 (2005); 10.1063/1.1999834 Electrical properties of sol-gel-derived Pb ( Zr 0.52 Ti 0.48 ) O 3 thin films on a PbTiO 3 -coated stainless steel substrate Appl. Phys. Lett. 81, 4805 (2002); 10.1063/1.1528288 Dielectric and piezoelectric properties of sol-gel derived lead magnesium niobium titanate films with different textures

Ferroelectric glass-ceramics of composition 0.90 (Ba 0.7 Sr 0.3 ) TiO 3 -0.10(B 2 O 3 :SiO 2 ) (0.90 BST:0.10 BS) synthesized by sol-gel method have been used for the preparation of dielectric thick-film inks. The particle dispersion of the glass-ceramic powders in the thick-film ink formulations have been studied through rheological measurements for fabricating thick-film capacitors by screen printing technique. The thick films derived from such glass-ceramics are found to sinter at considerably lower temperatures than the pure ceramic, and exhibit good dielectric characteristics with a tunability of 32% at 1 MHz under a dc bias field of 35 kV/cm.