Impurities and defects in Czochralski silicon: mechanisms of their effects on carrier lifetime, power conversion efficiency, and resistivity uniformity

Monocrystalline silicon grown by the Czochralski (CZ) method is the dominant material for crystalline silicon solar cells; in this material, impurities and defects directly determine wafer quality and device performance by governing three core metrics: minority carrier lifetime, power conversion efficiency, and resistivity uniformity. This review systematically summarizes the origins and spatial distribution of oxygen, carbon, dopants, metallic impurities, and grown-in defects in Czochralski silicon, the mechanisms by which they affect device performance, and the corresponding control strategies. Oxygen, predominantly interstitial, introduces deep-level recombination centers through precipitation and induces secondary defects, making it the most important factor degrading lifetime and power conversion efficiency; carbon, predominantly substitutional, indirectly amplifies recombination through complexes; the segregation of dopants and the evaporation of the volatile dopants dominate the spatial distribution of resistivity; and transition metals preferentially segregate at extended defects and amplify recombination. The control strategies reviewed include thermal-field and atmosphere optimization, crucible coating, magnetic-field regulation, gettering, and doping control. The core challenges are the precise decoupling of the coupled effects among multiple factors and the synergistic optimization of resistivity uniformity and minority carrier lifetime. The integration of multiphysics simulations, first-principles calculations, and data-driven soft-sensor modeling to establish a cross-scale research paradigm is expected to open new pathways for low-cost fabrication of high-quality n-type Czochralski silicon.