| 摘要 |
PURPOSE:To obtain a sufficient photoelectric conversion efficiency while p and n layers are made thinner by inserting a thin-film layer with a small refractive index than that of p-type and n-type semiconductor layers into the p-type and n-type semiconductor layers. CONSTITUTION:Light entering p layer is reflected by a thin-film layer 4 in n layer, the reflected light is reflected by a thin-film layer 7 in the p layer, and the reflection is repeated, thus confining light between two thin-film layers 4 and 7. Light can be effectively absorbed into a pn junction region sandwiched by the thin-film layers 4 and 7 and a high absorption coefficient can be obtained even if the p and n layers are made thinner. By setting a distance (d) between the thin-film layers 4 and 7 inserted into the p and n layers to values so that an expression I (n indicates the refractive index of p and n-type semiconductor layer constitution materials, Eg (ev) indicates a band gap energy, and d indicates the distance between the thin-film layers and is expressed by nm) can be met, light can be absorbed effectively by the pn junction region and a sufficient photoelectric conversion efficiency can be obtained while the p and n layers are made thinner. |
