The behavior of silicon materials in various production processes

The authors show in this paper the behavior of two different solar grades of silicon subjected to three different solar cell production processes. Two resistivities of CZ material and cast polycrystalline slices of Bayer “Baysix” silicon were used. They find that a standard sequence that does not include reduction of the front and back surface recombination velocities performs poorly with all materials. Reducing these contributions to recombination leads to cell efficiencies well over 15% for single crystal materials and to the mid 14% range for cast polycrystalline silicon when a high throughput, low cost production process is used. The high efficiency process produces CZ cells with efficiencies over 19% and polycrystalline cells over 16%