Abstract
Czochralski (Cz)-grown upgraded metallurgical-grade (UMG) silicon wafers degrade significantly during high-temperature processes, eroding their appeal as a low-cost alternative to conventional electronic-grade silicon wafers. However, the thermal degradation in UMG wafers can be delayed by utilizing a prefabrication annealing step. Based on this, a high-efficiency solar-cell process is modified by selecting a single-boron diffusion step and applying phosphorus-doped polycrystalline films as electron-selective contacts with excellent impurity-gettering properties to minimize the thermal budget. The application of this modified high-efficiency solar-cell process to n-type UMG-Cz wafers results in a solar cell with a conversion efficiency of 22.6% on a cell area of 2 × 2 cm2.
Original language | English |
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Article number | 1900297 |
Journal | Solar RRL |
Volume | 3 |
Issue number | 11 |
DOIs | |
Publication status | Published - 1 Nov 2019 |