Effect of oxygen doping in microcrystalline SiGe p-i-n solar cells

摘要

The effect of doping with oxygen the microcrystalline silicon-germanium absorber layer of single-junction p-i-n solar cells has been studied. In parallel, the absorber layer quality was measured by depositing absorber layers directly on glass and measuring their electrical properties. By doping the absorber layer with the optimum oxygen concentration (about 1.4×1019 cm−3), an increase in short-circuit current density of almost 4 mA/cm2 was achieved in 3 μm thick p-i-n solar cell. This effect is attributed to the oxygen doping compensating the space charges caused by the germanium dangling bonds rather than the direct defect passivation, as no drastic change in layer quality was measured.