An insight into dislocation density reduction in multicrystalline silicon

Dislocations can severely limit the conversion efficiency of multicrystalline silicon (mc-Si) solar cells by reducing minority carrier lifetime. As cell performance becomes increasingly bulk lifetime–limited, the importance of dislocation engineering increases too. This study reviews the literature on mc-Si solar cells; it focuses on the (i) impact of dislocations on cell performance, (ii) dislocation diagnostic skills, and (iii) dislocation engineering techniques during and after crystal growth. The driving forces in dislocation density reduction are further discussed by examining the dependence of dislocation motion on temperature, intrinsic and applied stresses, and on other defects, such as vacancies and impurities.