Development of New Type of Polymer Based Low Cost Encapsulation Technique for Amorphous Silicon Solar Modules

We have developed a new material that can be used for encapsulation of a-Si modules fabricated on TCO coated glass substrates. This is a polymer based material which can be sprayed on the back side of the module. The encapsulation is done by curing it at 60deg-70degC for a period of two hours. The material is transparent over a wavelength region of 300 nm-200 nm (transmission >95%) and can withstand temperature range -30degC to 100degC without any change of property. The efficacy of this type of encapsulation has been tested on a number of single and double junction modules. It has been found that after encapsulation the initial wattage of the modules increase by 5-6%. This may be due to relaxation of the cell structure deposited on the glass substrate during the curing of the encapsulant. This type of encapsulation has also been tested by exposure to atmosphere. It has been seen that for light soaked modules there is virtually no environmental degradation of the encapsulated modules. Thus we have been able to develop a cheap and comparatively simple encapsulation method for a-Si modules deposited on glass substrates