Numerical elimination methods of ITO cell contribution to dielectric spectra of ferroelectric liquid crystals

• Autorzy: Perkowski P.
• Języki publikacji: EN

Abstrakty

EN

Indium tin oxide (ITO) electrodes are widely used for liquid crystal applications as well as for measuring cells. Unfortunately, ITO layer possesses its own non zero resistivity R which produces (with the capacity C) the cut-off frequency f0 of RC circuit. Dielectric spectroscopy cannot be performed for high frequencies because of high frequency losses caused by the cell behaviour. Four procedures for estimating and extracting high frequency losses in ITO cells are presented and compared in this paper. Their limitations and viability are discussed.

Słowa kluczowe

EN

electric permittivity; high frequency losses; liquid crystal; dielectric spectroscopy

• Wydawca: Stowarzyszenie Elektryków Polskich ; Polska Akademia Nauk ; Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
• Czasopismo: Opto-Electronics Review
• Rocznik: 2011
• Tom: Vol. 19, No. 2
• Strony: 176--182
• Opis fizyczny: Bibliogr. 9 poz., wykr.

Twórcy

autor

Perkowski P.

• Institute of Applied Physics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warsaw, Poland,

Bibliografia

• [1] P. Perkowski: Dielectric spectroscopy of liquid crystals. Theoretical model of ITO electrodes influence on dielectric measurements. Opto-Electron. Rev. 17, 180-186, 2009.
• [2] P. Perkowski, D. Łada, K. Ogrodnik, J. Rutkowska, W. Piecek, and Z. Raszewski: Technical aspects of dielectric spectroscopy measurements of liquid crystal. Opto-Electron. Rev. 16, 271-276, 2008.
• [3] C.J.F. Böttcher and P. Bordewijk, Theory of Electric Polarization, Elsevier, 1978.
• [4] K.S. Cole and R.H. Cole: Dispersion and absorption in dielectrics. Alternating current characteristics. J. Chem. Phys. 9, 341-351, 1941.
• [5] R. Dhar: An impedance model to improve the higher frequency limit of electrical measurements on the capacitor made from electrodes of finite resistances. Indian J. Pure Ap. Phy. 42, 56-61, 2004.
• [6] M. Buivydas, F. Gouda, G. Andersson, S.T. Lagerwall, B. Stebler, J. Bömelburg, G. Heppke, and B. Gestblom: Collective and non-collective excitations in antiferroelectric and ferroelectric liquid crystals studied by dielectric relaxation spectroscopy and electro-optic measurements. Liq. Cryst. 23, 723-739, 1997.
• [7] S.K. Kundu, Y. Aoki, and B.K. Chaudhuri: Dielectric spectroscopy of an antiferroelectric liquid crystal showing an antiferroelectric-ferrielectric transition. Liq. Cryst. 31, 787-790, 2004.
• [8] M.B. Pandey, R. Dhar, and R. Dąbrowski: Dielectric spectroscopy of a newly synthesized chlorinated analogue of MHPOBC antiferroelectric liquid crystals. Ferroelectrics 343, 83-100, 2006.
• [9] G. Pandey, R. Dhar, V.K. Agrawal, and R. Dąbrowski: Characteristics of the dielectric relaxation modes of a newly synthesized fluorinated antiferroelectric liquid crystal 6F6B. Physica B 393, 167-174, 2007.