Collaborations

One of the important collaborative works is with SSN, Chennai to develop directionally solidified (DS) crystalline silicon material. To that end, a series of silicon sliced wafers were analyzed by Transmission/Reflection, FTIR and minority carrier life-time measurements. The non-metallic impurities originating from the interior parts of the DS furnace and the metallic impurities coming from the external source of the growth process have an adverse effect on the minority carrier life-time and thus on conversion efficiency of solar cells. This a concern which needs to be addressed by carefully monitoring not only average life time, but also life-time mapping to look at the inhomogeneity in the wafer and locate the impurity sites (Fig.1). It allows also to evaluate the growth dynamics, by probing life-time mapping at different depths of the ingot. This collaborative work will lead to indigenously developed monolike silicon fabrication. Further work on cell fabrication and characterization with these type of wafers are in pipeline.