| 摘要 |
PROBLEM TO BE SOLVED: To obtain a solar cell having a quantum well structure which is comparatively easily produced and superior in conversion efficiency by partly changing the thickness of a quantum well layer on the same plane. SOLUTION: A quantum well layer 14 does not show a uniform thickness over the entire surface but partly different and is formed e.g. such that the lower face of the layer 14 is flat and upper face is rough. At a comparatively thick part of the layer 14 can absorb light in a long wavelength range than those absorbed at other part, except the well layer, to thereby generate carriers, the same as in the conventional quantum well layer, and the carriers in the quantum well can be escaped from this well through a thin part of the layer 14, having a high quantum level. As the result, the probability that the carriers in the quantum well disappear due to the recombination in this well is reduced enough to take them out effectively as a current. |
