G W Mbise et al 1997 J. Phys. D: Appl. Phys. 30 2103 doi:10.1088/0022-3727/30/15/001
G W Mbise
, D Le Bellac
, G A Niklasson§ and C G Granqvist§
This review is devoted to the angular selectivity that can be obtained in thin films prepared under conditions such that they contain inclined absorbing regions of sizes much smaller than the wavelength of visible light. The films are of considerable interest as window coatings for energy-conscious architecture and, potentially, in the automotive sector. The theoretical basis for modelling the optical properties is presented, comprising rigorous bounds on the dielectric function, effective medium theories pertinent to different microgeometries and equations for treating the optics of anisotropic thin films. Experimental data are reported for films made by oblique-angle evaporation of Cr and for reactive and non-reactive oblique-angle sputtering of Cr, Al, Ti and W. The highest angular selectivity was obtained with evaporated Cr, whereas the highest luminous transmittance, combined with some angular selectivity, was found with reactively sputtered Al. Films made from Ti showed angular selectivity mainly in the infrared, whereas films made from W could display angular selective electrochromism. Samples of several types were subjected to elaborate theoretical analysis using effective-medium theories and it was seen that theory and experiment could be reconciled using plausible parameters to specify the microstructures of the films. Thus it appears that the angular, spectral and polarization dependences of obliquely deposited films can be understood, at least approximately, in terms of conceptually simple theoretical models.
78.20.Bh Theory, models, and numerical simulation
78.20.Jq Electrooptical effects
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
68.55.A- Nucleation and growth
78.66.Bz Metals and metallic alloys
Issue 15 (7 August 1997)
Received 30 October 1996
G W Mbise et al 1997 J. Phys. D: Appl. Phys. 30 2103
K O Kvashnina et al 2009 J. Phys.: Conf. Ser. 190 012191
K-M Wang et al 2007 J. Phys. D: Appl. Phys. 40 4740
Stephen Boughn and Tony Rothman 2006 Class. Quantum Grav. 23 5839
Günter Plunien et al 2007 Class. Quantum Grav. 24 4361
J. L. Hora et al. 2008 The Astronomical Journal 135 726
R A Gordon et al 2009 J. Phys.: Conf. Ser. 190 012047
I A Buyanova et al 2006 J. Phys.: Condens. Matter 18 449
P. Kharb et al. 2006 ApJ 652 177
Tetsuya Takeuchi et al 2002 J. Phys.: Condens. Matter 14 L261