The influence of an annealing step at about 500°C after emitter diffusion of multicrystalline solar cells is investigated. Neighboring wafers from a silicon ingot were processed using different annealing durations and temperatures. The efficiency of the cells was measured and detailed light beam induced current measurements were performed. These show that mainly areas with high contents of precipitates near the crucible walls are affected by the anneal. An efficiency increase from 14.5 to 15.4% by a 2h anneal at 500°C was observed. The effect seems to be more likely external than internal gettering

Minority carrier recombination is studied in multicrystalline ingot cast silicon solar cells. The normalized recombination strength Gamma of dislocations is obtained by correlating topograms of the internal quantum efficiency (IQE) with those of the dislocation density rho. Gamma is obtained by fitting an extended theory of Donolato to the experimental data. The measured Gamma-values vary significantly between adjacent dislocation clusters and correlate with the spatial pattern of the dislocations. All Gamma-values are strongly dependent on the parameters of the solar cell process. The influence of phosphorus diffusion and hydrogenation is shown. After solidification of the silicon, impurities from the crucible enter the ingot and deteriorate its border regions during cooling to room temperature. These deteriorated border regions can be significantly improved by an additional low temperature anneal that is applied after phosphorus diffusion. The experiments indicate that the mechanism of the anneal is external phosphorus gettering into the emitter

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In this work, a novel diluted carbonate/bicarbonate solution was applied for texturization of monocrystalline silicon for solar cells. The content of reactants in the solution was decreased 20 times with respect to the previously optimum found by our group and 12 times with respect to the lowest values reported in the literature as optimum. The use of this low‐cost and nonhazardous solution, free of additives as isopropyl alcohol, can reduce costs in solar cell processing. Copyright © 2011 John Wiley & Sons, Ltd.