| 摘要 |
PURPOSE:To thin Si layers and unnecessitate the special use of color filters by having the first amorphous photovoltaic element formed on a substrate, a clear insulation layer formed on this element, and the second amorphous photovoltaic element formed on this insulation layer. CONSTITUTION:When a light L comes incident from the side of a clear conductive film 31, a photo diode PD1 closer to the photo receiving plane increases the short wave sensitivity, and a deeper photo diode PD2 increases the long wavelength sensitivity. If the short circuit currents produced by the photo reception of these photo diodes PD1 and PD2 are Isc1 and Isc2, respectively, the wavelength dependence of the current ratio Isc2/Isc1 is as shown in the diagram: the ratio Isc2/Isc1 of short circuit current has the relation of 1 to 1 with respect to wavelength. Then, the current ratio Isc2/Isc1 is obtained by measuring the short circuit currents of the photo diodes PD1 and PD2 when receiving a color light; thereby, the wavelength of received light can be determined on the basis of the characteristic shown in the diagram. |
