Abstract: Production of a silicon wafer coated with a passivation layer. The coated silicon wafer may be suitable for use in photovoltaic cells which convert energy from light impinging on the front face of the cell into electrical energy.

Abstract: Production of a silicon wafer coated with a passivation layer. The coated silicon wafer may be suitable for use in photovoltaic cells which convert energy from light impinging on the front face of the cell into electrical energy.

Abstract: An apparatus for plasma treating a substrate comprises a high voltage source of frequency 3 kHz to 30 kHz connected to at least one needle electrode (11) positioned within a channel (16) inside a dielectric housing (14) having an inlet for process gas and an outlet. The channel (16) has an entry (16a) which forms the said inlet for process gas and an exit (16e) into the dielectric housing arranged so that process gas flows from the inlet through the channel (16) past the electrode (11) to the outlet of the dielectric housing. The apparatus includes means for introducing an atomised surface treatment agent in the dielectric housing, and support means (27, 28) for the substrate (25) adjacent to the outlet of the dielectric housing.

Abstract: A process for plasma treating a substrate comprises applying a radio frequency high voltage to at least one electrode positioned within a dielectric housing having an inlet and an outlet while causing a process gas, usually comprising helium, to flow from the inlet past the electrode to the outlet, thereby generating a non-equilibrium atmospheric pressure plasma. An atomised or gaseous surface treatment agent is incorporated in the non-equilibrium atmospheric pressure plasma. The substrate is positioned adjacent to the plasma outlet so that the surface is in contact with the plasma and is moved relative to the plasma outlet. The velocity of the process gas flowing past the electrode is less than 100 m/s. Process gas is also injected into the dielectric housing at a velocity greater than 100 m/s. The volume ratio of process gas injected at a velocity greater than 100 m/s to process gas flowing past the electrode at less than 100 m/s is from 1:20 to 5:1.

Abstract: A process for plasma treating a substrate comprises applying a radio frequency high voltage to at least one electrode positioned within a dielectric housing having an inlet and an outlet while causing a process gas to flow from the inlet past the electrode to the outlet, thereby generating a non-equilibrium atmospheric pressure plasma. An atomized or gaseous surface treatment agent is incorporated in the non-equilibrium atmospheric pressure plasma. The substrate is positioned adjacent to the plasma outlet so that the surface is in contact with the plasma and is moved relative to the plasma outlet. The flow of process gas and the gap between the plasma outlet and the substrate are controlled so that the process gas has a turbulent flow regime within the dielectric housing.