Abstract: The present application relates a solar cell, a photovoltaic device and a photovoltaic system. The solar cell includes a substrate, a first passivation layer, and a second passivation layer. The substrate includes a first surface and a second surface opposite to each other along a thickness direction of the substrate. The first passivation layer is disposed on the first surface of the substrate. The second passivation layer is disposed on a side of the first passivation layer away from the substrate. A material of the first passivation layer is the same as that of the second passivation layer. An atomic packing density of the first passivation layer is higher than that of the second passivation layer. An average thickness of the first passivation layer is smaller than that of the second passivation layer.

Abstract: A solar cell and a manufacturing method thereof, and a photovoltaic system. The solar cell includes: a substrate layer including a first surface and a second surface arranged oppositely along a thickness direction thereof; a tunnel oxide layer, a first doped polysilicon layer, and a first passivation layer sequentially arranged on the first surface of the substrate layer in a direction gradually away from the substrate layer; and a first finger electrode layer, at least one of the first fingers being arranged in first connection holes, bottoms of the first connection holes being located in the first doped polysilicon layer, and the first fingers passing through the first connection holes corresponding thereto to be electrically connected to the first doped polysilicon layer; and in the first direction, widths of the first connection holes being all less than widths of the first fingers corresponding to the first connection holes.

Abstract: The present application provides a film preparation method, a solar cell, a photovoltaic device, and a photovoltaic system. The film preparation method includes forming a first passivation layer on a first surface of a substrate by using a first preparation technique; and forming a second passivation layer on a surface of the first passivation layer away from the substrate by using a second preparation technique, a material of the second passivation layer is the same as that of the first passivation layer; wherein a passivation layer forming speed of the first preparation technique is lower than that of the second preparation technique, and a passivation effect of the first passivation layer is better than that of the second passivation layer.

Abstract: A method for synthesizing a copper-silver alloy includes an ink preparation step, a coating step, a crystal nucleus formation step and a crystal nucleus synthesis step. In the ink preparation step, a copper salt particle, an amine-based solvent, and a silver salt particle are mixed, thereby preparing a copper-silver ink. In the coating step, a member to be coated is coated with the copper-silver ink. In the crystal nucleus formation step, at least one of a crystal nucleus of copper having a crystal grain diameter of 0.2 ?m or less and a crystal nucleus of silver having a crystal grain diameter of 0.2 ?m or less is formed from the copper-silver ink. In the crystal nucleus synthesis step, the crystal nucleus of copper and the crystal nucleus of silver are synthesized.

Abstract: A method for synthesizing a copper-silver alloy includes an ink preparation step, a coating step, a crystal nucleus formation step and a crystal nucleus synthesis step. In the ink preparation step, a copper salt particle, an amine-based solvent, and a silver salt particle are mixed, thereby preparing a copper-silver ink. In the coating step, a member to be coated is coated with the copper-silver ink. In the crystal nucleus formation step, at least one of a crystal nucleus of copper having a crystal grain diameter of 0.2 ?m or less and a crystal nucleus of silver having a crystal grain diameter of 0.2 ?m or less is formed from the copper-silver ink. In the crystal nucleus synthesis step, the crystal nucleus of copper and the crystal nucleus of silver are synthesized.

Abstract: A method for synthesizing a copper-silver alloy includes an ink preparation step, a coating step, a crystal nucleus formation step and a crystal nucleus synthesis step. In the ink preparation step, a copper salt particle, an amine-based solvent, and a silver salt particle are mixed, thereby preparing a copper-silver ink. In the coating step, a member to be coated is coated with the copper-silver ink. In the crystal nucleus formation step, at least one of a crystal nucleus of copper having a crystal grain diameter of 0.2 ?m or less and a crystal nucleus of silver having a crystal grain diameter of 0.2 ?m or less is formed from the copper-silver ink. In the crystal nucleus synthesis step, the crystal nucleus of copper and the crystal nucleus of silver are synthesized.

Abstract: A method for synthesizing a copper-silver alloy includes an ink preparation step, a coating step, a crystal nucleus formation step and a crystal nucleus synthesis step. In the ink preparation step, a copper salt particle, an amine-based solvent, and a silver salt particle are mixed, thereby preparing a copper-silver ink. In the coating step, a member to be coated is coated with the copper-silver ink. In the crystal nucleus formation step, at least one of a crystal nucleus of copper having a crystal grain diameter of 0.2 ?m or less and a crystal nucleus of silver having a crystal grain diameter of 0.2 ?m or less is formed from the copper-silver ink. In the crystal nucleus synthesis step, the crystal nucleus of copper and the crystal nucleus of silver are synthesized.

Abstract: A system for pest control in a confined space using flue gas from a biomass power plant is disclosed. The system contains a flue gas treatment device including a discharge pipe; a storage tank of treated flue gas; a control unit; a first regulating valve; a first pressure monitoring sensor; a carbon dioxide concentration monitoring sensor; and a first atmospheric valve.

Abstract: A method for pest control in a confined space using flue gas from a biomass power plant. The method includes: treating flue gas from a biomass power plant to yield treated flue gas having a volume concentration of carbon dioxide exceeding 85 volume %, and conducting pest control in a confined space according to the following steps: continuously aerating the confined space with the treated flue gas during a fallow period to allow a gas pressure in the confined space to reach between 0.110 and 0.140 megapascal of absolute pressure and the volume concentration of carbon dioxide in the confined space to reach between 50 and 90 volume %.

Abstract: A method for pest control in a confined space using flue gas from a biomass power plant. The method includes: treating flue gas from a biomass power plant to yield treated flue gas having a volume concentration of carbon dioxide exceeding 85 volume %, and conducting pest control in a confined space according to the following steps: continuously aerating the confined space with the treated flue gas during a fallow period to allow a gas pressure in the confined space to reach between 0.110 and 0.140 megapascal of absolute pressure and the volume concentration of carbon dioxide in the confined space to reach between 50 and 90 volume %.