Morphology of SiO2 films as a key factor in alignment of liquid crystals with negative dielectric anisotropy

Volodymyr Tkachenko; Antigone Marino; Eva Otón; Noureddine Bennis; Josè Manuel Otón

doi:10.3762/bjnano.7.167

Morphology of SiO₂ films as a key factor in alignment of liquid crystals with negative dielectric anisotropy

Beilstein J Nanotechnol. 2016 Nov 17:7:1743-1748. doi: 10.3762/bjnano.7.167. eCollection 2016.

Authors

Volodymyr Tkachenko¹, Antigone Marino¹, Eva Otón², Noureddine Bennis³, Josè Manuel Otón²

Affiliations

¹ CNR-ISASI and Physics Department, University of Naples Federico II, Via Cinthia Monte S. Angelo, 80126, Naples, Italy.
² CEMDATIC, E.T.S.I. Telecomunicación, Universidad Politécnica de Madrid, Avda. Complutense 30, 28040 Madrid, Spain.
³ Institute of Applied Physics, Military University of Technology, 00-908 Warsaw, Poland.

Abstract

Control of liquid crystal (LC) orientation using a proper SiO₂ alignment layer is essential for the optimization of vertically aligned nematic (VAN) displays. With this aim, we studied the optical anisotropy of thin SiO₂ films by generalized ellipsometry as a function of deposition angle. The columnar SiO₂ structure orientation measured by a noninvasive ellipsometry technique is reported for the first time, and its morphology influence on the LC alignment is demonstrated for large deposition angles.

Keywords: anisotropy; ellipsometry; liquid crystal alignment; morphology; thin film.