The asymmetric insertion of oxide layers having mixed conduction properties (ionic and electronic) in liquid crystal cells induces various kinds of electro-optical response of the liquid crystals, and this behaviour has been related to the structural differences of the inserted films. In this work, it is reported a structural study of such oxide films deposited on indium tin oxide (ITO) covered glasses. To have further confirmations of the model and a better understanding of the basic mechanism underlying the rectification effect and the connections with the structural and electrical properties of the films, Vanadium oxide layers have been studied before and after thermal treatment. Moreover the gelification via spin coating has been implemented and the optimisation tests of various relevant parameters have been performed. The chemical, structural and optical evolution has been extensively investigated as a function of the thermal annealing treatment, by performing vibrational spectroscopy analysis (micro-Raman and IR) and impedance spectroscopy characterization, before testing the films into the NLC cells.
Asymmetric response to electric field in nematic liquid crystal cells containing vanadium oxide thin films prepared by sol-gel synthesis
Castriota M;Versace C;STRANGI, Giuseppe;Scaramuzza N.
2005-01-01
Abstract
The asymmetric insertion of oxide layers having mixed conduction properties (ionic and electronic) in liquid crystal cells induces various kinds of electro-optical response of the liquid crystals, and this behaviour has been related to the structural differences of the inserted films. In this work, it is reported a structural study of such oxide films deposited on indium tin oxide (ITO) covered glasses. To have further confirmations of the model and a better understanding of the basic mechanism underlying the rectification effect and the connections with the structural and electrical properties of the films, Vanadium oxide layers have been studied before and after thermal treatment. Moreover the gelification via spin coating has been implemented and the optimisation tests of various relevant parameters have been performed. The chemical, structural and optical evolution has been extensively investigated as a function of the thermal annealing treatment, by performing vibrational spectroscopy analysis (micro-Raman and IR) and impedance spectroscopy characterization, before testing the films into the NLC cells.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
