Phone: þ00 1 416 946 7372, Fax: þ00 1 416 971 2326The DC saddle-field (DCSF) glow discharge method was used to deposit intrinsic a-Si:H onto c-Si to passivate the c-Si surface. The effective minority carrier lifetime in the heterostructures as a function of the excess minority carrier density in the c-Si wafers was measured. The results were then analyzed in the context of recombination associated with interface defect states using three known recombination models. The defect density and the charge density at the interface are inferred. In addition subsequent annealing of the samples was studied. It is shown that for our intrinsic a-Si:H samples improvements in surface passivation are directly correlated with the reduction of interface defects and not the reduction of minority carrier concentration at the interface due to electric field. We have achieved excellent surface passivation with effective carrier lifetime >4 ms for an intrinsic a-Si:H sample deposited at a process temperature of 200 8C and thickness of about 30 nm. It is also demonstrated that subsequent annealing, at 240 8C, of the samples which were prepared at process temperatures <240 8C greatly increases the effective lifetime.

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The DC saddle field glow discharge method was used to deposit a-Si:H in order to passivate c-Si surfaces. The process temperature and the thickness of the a-Si:H films were varied. In addition subsequent annealing of the smaples were studied. Passivation quality of the a-Si:H overlayers were studied by measuring the effective minority carrier lifetime in the heterostructures as a function of the minority carrier density in the c-Si wafer. These results are then used to model the surface recombination mechanism in our samples. The defect density and the charge density at the interface are inferred which helps us to distinguish between the effects of electric field and chemical passivation at the interface. It is shown that for our intrinsic a-Si:H samples improvements in surface passivation are directly correlated with the reduction of interface defect density and field effect passivation is minimal. We have achieved surface passivation with effective carrier lifetime > 5 ms for a 40 nm intrinsic a-Si:H sample deposited at a process temperature of 200 o C. It is also demonstrated that subsequent annealing, at 240 o C, of the samples which were prepared at process temperatures < 240 o C drastically increases the effective lifetime.