| abstract |
Device (1) for producing silicon blocks (30) for photovoltaic applications comprising a. a container (2) for receiving a silicon melt (3) i. a bottom wall (5) and ii. at least one side wall (6), b. Means for reducing the diffusion of impurities from at least one of the walls (5, 6) of the container (2) into the silicon melt and the silicon crystal (3), c. wherein the means for reducing the diffusion of impurities comprise at least one covering element (4; 4a) for at least partially covering at least one of the walls (5, 6) of the container (1), d. wherein the cover element (4; 4a) is formed in such a way that the bottom wall (5) of the container (2) is at least 50% coverable by the cover element (4; 4a), and e. wherein the cover element (4; 4a) has at least one component selected from the group of refractory metals, their compounds and also silicon dioxide (SiO 2 ), silicon carbide (SiC) and silicon nitride (Si 3 N 4 ), and f. wherein the at least one cover element (4; 4a) is designed as an insert plate (4) for insertion into the container (2), and G. wherein the cover member (4; 4a) is made of a material having a melting point which is above the melting point of silicon, and H. wherein the cover element (4; 4a) is closed-pored, and i. wherein the cover member (4; 4a) has less than 0.1% impurities. |