Impurity-to-efficiency simulator: predictive simulation of silicon solar cell performance based on iron content and distribution

We present a simulation tool that predicts solar cell efficiency based on iron content in as‐grown wafer and solar cell processing conditions. This “impurity‐to‐efficiency” (I2E) simulation tool consists of three serial components, which are independently and jointly validated using published experimental results: (1) a kinetic model that calculates changes in the distribution of iron and phosphorus atoms during annealing; (2) an electronic model that predicts depth‐dependent minority carrier lifetime based on iron distribution; and (3) a device simulator that predicts solar cell performance based on the minority carrier lifetime distribution throughout the wafer and the device architecture. The I2E model is demonstrated to be an effective predictor of cell performance for both single‐crystalline and multi‐crystalline silicon solar cells. We demonstrate the process optimization potential for the I2E simulator by analyzing efficiency improvements obtained using low‐temperature annealing, a processing concept that has been successfully applied to achieve higher solar cell efficiencies on Fe‐contaminated materials. Copyright © 2010 John Wiley & Sons, Ltd. A simulation tool is presented and validated that predicts solar cell efficiency based on iron content and distribution in as‐grown wafer and solar cell processing conditions, including time‐temperature profile and device‐related parameters like surface recombination velocities and resistances. Outputs of this “impurity‐to‐efficiency” (I2E) simulation tool are post‐process iron content and distribution, electron lifetime as a function of wafer depth and solar cell performance parameters, like efficiency, open circuit voltage, and short circuit current.