Thin walled, shaped crystals, for solar cell mfr. - comprises forming melt using radiation, maintaining temp. with electric current and pulling crystal

摘要

Thin walled, shaped crystals are pulled from a fluid reservoir which has an electrical conductivity which is substantially higher than that of adjacent solid regions. In the starting material, a pool of molten material is formed which is contacted at certain places by electrodes. An electrical bias is applied to the electrodes causing a current through the melt. The melt is contacted with a seed crystal which is slowly pulled away. An equilibrium situation is established in which the pool has the required size for the shape being pulled. Pref. 2 electrodes are used which are pref. wetted wall by the melt. The molten material used may be a melt soln. including the material to be pulled. The material used for the crystal growth is pref. provided as solid material. USE/ADVANTAGE - The process uses radiation to form the initial melt which can then be increased and maintained by the electrical current. This allows increased freedom of shape, vol. and temp. compared with conventional heating methods such as laser, electron-beam or mirror-heating. The process allows the pulling of thin crystals of up to 10 cm wide as well as other shapes, including hollow tubes or many sided crystals. The method is used for the mfr. of the starting material for solar cells.