Windows visible transmittance

Polycrystalline ZnO for window layers in solar cells are most frequently prepared by magnetron sputtering. Optimized layers have resistivities of 1.5-2x10 " Ocm with Hall mobilities of up to 60 cmWs, refractive indices of approximately 2.0 and an average transmittance of 85 % in the visible range. The best values of the mobility in optimized films have reached the... 

An important and widely encountered noise source, one that is proportional to transmittance, results from failure to position sample and reference cells repro-ducibly with respect to the beam during replicate transmittance measurements. All cells have minor imperfections. As a consequence, reflection and. scattering losses vary as different sections of the cell window arc exposed to the beam small variations in transmittance result. Rothman, Crouch, and Ingle have shown that this uncertainly often is the most common limitation to the accuracy of high-quality ultraviolet-visible spectrophotometers. It is also a serious source of uncertainty in infrared instruments. 

Visible Light Transmittance - The amount of visible light that passes through the glazing material of a window, expressed as a percentage. 

Transmission. The transmittance of glasses is limited by electronic excitiations and light scattering in the UV, by vibronic excitations in the IR, and by reflections and impurity absorptions within the transmission window (in the visible part of the spectmm) Fig. 3.4-27. The UV absorption edge is temperature dependent. An example is shown in Fig. 3.4-28. 

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