Improvements to the solar cell efficiency and production yields of low-lifetime wafers with effective phosphorus gettering

• Variable-temperature gettering improves efficiencies when the wafer quality is poor.
• High-quality wafers need not be used for variable-temperature gettering.
• The proposed gettering method is based on an existing diffusion process.
• It has a potential interest for hot-spot prevention.

This research focuses on the improvement of solar cell efficiencies in low-lifetime wafers by implementing an appropriate gettering method of the diffusion process. The study also considers a reduction in the value of the reverse current at −12 V, an important electrical parameter related to the hot-spot heating of solar cells and modules, to improve the product's quality during commercial mass production. A practical solar cell production case study is examined to illustrate the use of the proposed method. The results of this case study indicate that variable-temperature gettering significantly improves solar cell efficiencies by 0.14% compared to constant-temperature methods when the wafer quality is poor. Moreover, this study finds that variable-temperature gettering raises production yields of low quality wafers by more than 30% by restraining the measurement value of the reverse current at −12 V during solar cell manufacturing.