Stable Metallization Systems for Solar Cells

Reactively sputtered transition metal nitride layers can efficiently prevent the interdiffusion between adjoining materials during heat treatments up to 15 min, 800 °C. The layers are electrically metallic and the typical contact resistivity of ≦ 10−4 Ωcm2 between the nitride layer and a solar-cell-type Si substrate is adequate for solar cell applications. Stable test cells using a titanium nitride layer in the metallization are fabricated. Nitride layers can be converted into oxide layers by thermal oxidation. The optical properties of TiO2 layers are comparable with those of TiOx layers used as an antireflecting coating in solar cells.