About the Stability of the Photovoltaic Characteristics of Hydrogenated Solar Cells Made from RAD Silicon Ribbons

摘要

This paper reports on the stability of the photovoltaic characteristics of hydrogenated solar cells made from RAD polycrystalline silicon ribbons. The hydrogenation was conducted on uncoated metallized cells by an implantation technique using an ion source of the Kaufman-type. The stable part of the improvement of the solar cell characteristics which follows from the hydrogenation is ascribed to the neutralization of ''dangling'' bonds in the bulk and at boundaries by formation of energetic Si-H bonds. The decay of the photocurrent density close to the prehydrogenation level within a few thousand hours appears to be bound to a decrease of the concentration of (interstitial) hydrogen near to the surface which in turn restores the original reflectivity. These interpretations are supported by the preliminary results of studies on the physico-chemical properties of hydrogen in polycrystalline silicon. (ERA citation 11:015870)