Germanium-doped crystalline silicon: Effects of germanium doping on boron-related defects

• We review the effects of Ge doping on B-related defects in crystalline silicon.
• Ge doping increases the diffusion barriers of Fei and O2i.
• Ge–B complexes increase the formation energies of FeB pairs and B–O defects.
• The saturated concentration of B–O defects can be reduced due to Ge doping.
• Ge doping improves the efficiency of solar cells and the power output of corresponding modules.

Recently it has been recognized that germanium (Ge) doping can be used for microelectronics and photovoltaic devices. This article reviews the recent results about the effects of Ge doping on boron-related defects in crystalline silicon. Behavior of Ge interacting with the acceptor dopants is also discussed therein. In addition, the article provides a comprehensive review on the effect of Ge doping to the formation of iron–boron pairs and boron–oxygen defects that is responsible for the light induced degradation (LID) of the carrier lifetime. The improvement silicon-based solar cells application from Ge doping is discussed as well, including the increment of cell efficiency and the power output of corresponding modules under sunlight illumination.