Angle-resolved optical characterisation of an electrochromic device

An electrochromic prototype with WO3 and NiO as electrochromic layers was analysed in an absolute spectrophotometer. The electrochromic glazing was measured in combination with a clear float glass and a low-e glass in order to simulate a 'real' window. Similar measurements were performed on a commercial electrochromic product, i.e., a Gentex Night Vision Safety(TM) (NVS(R)) mirror from Gentex Corporation, and the results were compared. The spectral transmittance was measured, in bleached and coloured state, over the solar wavelength range at the angles of incidence, phi = 0, 40, 60 and 70 degrees The direct solar transmittance, T-sol, the visual transmittance, T-vis, and the angular dependence for these parameters were calculated. (C) 2000 Elsevier Science Ltd. All rights reserved.