| 摘要 |
A double photoelectrochemical cell for converting solar energy directly to electricity. The device in one embodiment has two semiconductors which are separated from each other by a polymer electrolyte. The two semiconductors have a different band gap; for example, one is n-type CdS and the other is p-type CdTe. The polymer electrolyte, for example, is a thin film polyethylene oxide acting as a polymer matrix containing a polysulfide redox couple, for example, Na2S4. The polymer electrolyte is transparent, insulating and capable of transporting ions. At least one of the semiconductors is semi-transparent. The short wavelengths of light are absorbed by the semi-transparent wide band gap semiconductor, and the long wavelengths pass therethrough, and through the polymer film electrolyte, and are absorbed by the narrow band gap semiconductor. The output of the cell is double; one from each semiconductor, i.e. they are series-connected. Output voltage, for example, is about 0.625 volts. The theoretical efficiencies in the example are about 35%, compared with about 25% for a standard photovoltaic cell, having a single junction. Also included is a method of manufacturing such a cell.
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