| 摘要 |
PURPOSE:To improve conversion efficiency by setting an n<+> layer or a p<+> layer corresponding to a collector for electrons or holes to an intermediate electrode. CONSTITUTION:A p type layer and an n type layer are arranged in order of said layers from the substrate 9 side in lower cell layers 10 by an n-p junction of In0.7Ga0.3As0.64P0.36 disposed on a substrate 9. An intermediate layer 11 consists of the n<+> layer as an excess second conduction type layer in In0.52Al0.48As. An n type layer and a p type layer are arranged in order of said layers from the lower layer 10 side in upper cell layers 12 of a p-n junction in InP. Electrons excited by light in the layers 12 proceed to the layer 11 as the intermediate electrode 13. However, electrons are stored in the layer 11 because the n layer in the layers 10 as lower layers functions as a barrier. On the other hand, holes optically pumped by the layers 12 proceed to the surface, and stored in the layer 12. Electrons optically pumped by the layers 10 are stored in the layer 11 because the n layer in the layers 12 similarly functions as a barrier, and collect to a hole electrode 15. Accordingly, holes can be extracted from electrodes 14 and the electrode 15 and electrons from the intermediate electrode 13. |
