The performance of 〈indium-tin-oxide (ITO)/silicon oxide/n-Si(100)〉 junction solar cells is improved by immersing Si wafers in a potassium cyanide solution before the ITO deposition. It is found from x-ray photoelectron spectroscopy measurements that about 3% monolayer cyanide (CN−) ions are present on the Si surface after the cyanide treatment. The temperature dependence of the current–voltage curves shows that the band bending in n-Si is increased by the cyanide treatment. The increase in the band bending is attributed to an upward Si band edge shift caused by the presence of CN− ions at the oxide/Si interface and/or in the oxide layer. Conductance–voltage measurements show that the density of trap states considerably decreases after the cyanide treatment. The conductance decrease is attributed to the passivation of interface states by the adsorption of CN− ions on Si dangling bonds.

We attempted the quantification of carbon concentration in Czochralski-grown Si crystals for solar cells by luminescence activation in the concentration range lower than the detection limit of IR absorption spectroscopy. A positive correlation was found between the relative intensity of the C-line and the substitutional carbon (Cs) concentration determined by IR absorption in the low 1015 cm−3 range. The detection limit was estimated to be approximately 5 × 1012 cm−3. We measured and compared the Cs concentrations in the wafers sliced from ingots grown under different conditions. The variations in Cs concentrations in the respective ingots were consistent with the segregation effect.

The photovoltage and the fill factor o f (indium-tin oxide (ITO)/silicon oxide/polycrystalline n-Si) junction solar cells are increased b y immersing S i i n a potassium cyanide solution before the deposition o f a n I T 0 film. Measurements o f the temperature dependence o f the dark current-voltage curves show that the mechanism o f the current flow through the S i depletion layer is changed from trap-assisted multistep tunneling t o thermionic-assisted tunneling b y the KCN treatment, indicating a decrease in the density o f the trap states i n the S i depletion layer. Measurements o f the electrode conductance also show that the trap density is greatly reduced b y the KCN treatment. The improvement o f the electrical characteristics is attributed t o the decrease i n the trap density and an increase i n the barrier height i n n-Si caused b y t h e inclusion o f cyanide ions at t h e oxide/Si interface and/or i n t h e silicon oxide layer.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.210.126.199 Downloaded on 2015-06-20 to IP

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