| 摘要 |
PURPOSE:To provide the highly efficient solar battery, by expediting the diffusion speed of optically excited electrons and holes, thereby reducing recombination probability. CONSTITUTION:The band structure of the solar battery comprises a conductor 1, a valence band 2, and a Fermi level 3. Added impurities for obtaining a P type have a concentration gradient from a P region to an N region, and the concentration gradually becomes low. At the center of a P-N junction, the concentration of the added material is almost zero. Then, impurities for obtaining an N type are added so as to obtain high concentration gradually, and the N region is formed. In the P-N junction solar battery formed in this way, the impurity concentration becomes 10<18>-10<19>pieces/cc only at the region, which is a part of the other end of the junction of the P region and the N region. The concentration in the region of the most other part becomes less than 10<18> pieces/cc. |
