| 摘要 |
PURPOSE:To obtain a solar cell wherein incident light in a long wavelength region is absorbed and photoelectric conversion efficiency is increased by a method wherein a quantum well layer or a superlattice layer is formed in a bonding part. CONSTITUTION:Two semiconductor layers out of an n-type semiconductor layer 2, a p-type semiconductor layer 5 and an i-type semiconductor layer are bonded in a bonding part, and incident light L is photoelectrically converted and taken out as electric power from electrodes 1, 6 connected respectively to the two semiconductor layers. In such a solar cell, a quantum well layer 3 or a superlattice layer is formed in the bonding part. Alternatively, a graded layer which has changed a potential continuously is formed at least in the quantum well layer 3 or the superlattice layer and between the two semiconductor layers. For example, an n-type semiconductor layer 2 and a p-type semiconductor layer 5 in which crystal Si has been doped respectively with As and Ga are formed, a mixed-crystal semiconductor layer in which the composition ratio of Si to Ge is 80% to 20% is formed between them and it is used as a quantum well layer 3. |
