OXIDE SEMICONDUCTORS IN PHOTOELECTROCHEMICAL CONVERSION OF SOLAR-ENERGY
OXIDE SEMICONDUCTORS IN PHOTOELECTROCHEMICAL CONVERSION OF SOLAR-ENERGY
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DOI：
10.1016/0038-092x(80)90405-3
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发表时间：
1980-01-01
期刊：
影响因子：
6.7
通讯作者：
SCAIFE, DE
中科院分区：
文献类型：
--
作者：
SCAIFE, DE
广泛的氧化物被用作光电化学电池的阳极，用于将太阳能转化为电能或氢气。全文采用半导体-电解质界面的肖特基势垒模型。不包含部分填充d能级的（a）型氧化物符合平带电位V fb（SHE）和带隙E g之间的关系，V FB（SHE）= 2.94-E g，这基本上排除了发现同时具有小带隙和大负平带电位的（a）型氧化物的可能性，这是在无偏光电解水中有效操作所需的。将此关系并入光电流的肖特基势垒公式中，使得能够计算（a）型氧化物的转换效率。对于空气质量1辐射，预测的最大效率转换为氢为3.4%，为E g= 3 eV的无偏光电解; 6.3%为E g= 2.4 eV的串联电压偏置的光电解;和4.7%为E g= 2.2 eV的pH值偏置的光电解。对于具有氧化还原操作的动力电池，预测（a）型氧化物对于E g= 2.4 eV给出5- 6%的效率，其中氧化还原对具有不小于0.8 V的标准电势。具有（a）型氧化物阳极的光电化学电池的高效率操作似乎仅在某些特殊情况下是可能的。所观察到的稳定性与其计算的热力学稳定性对光阳极溶解的氧化物范围广泛的比较表明，在光电解的氧化物阳极的氧过电位可能是小的，和氧化物阳极的长期稳定性的估计的热力学方法是有用的。获得令人满意的效率与氧化物含有部分填充的d-水平的前景也进行了检查，并发现受到严重限制的同时要求的稳定性，平带电位，和带隙。最后提出了进一步研究的建议。
A wide range of oxides is examined for use as anodes in photoelectrochemical cells for the conversion of solar energy into electrical power or hydrogen. The Schottky barrier model of the semi-conductor-electrolyte interface is used throughout. Type (a) oxides, not containing partly-filled d-levels, are found to conform to the relationship between flat band potential, V fb (SHE), and band gap, E g, V FB (SHE)= 2.94− E g which essentially rules out the possibility of finding type (a) oxides with simultaneously the small band gap and large negative flat band potential required for efficient operation in the unbiased photoelectrolysis of water. Incorporation of this realationship into the Schottky barrier formula for photocurrent enables the calculation of efficiencies of conversion for type (a) oxides. For air mass 1 radiation, the predicted maximum efficiency of conversion to hydrogen is 3.4 per cent for E g= 3 eV for unbiased photoelectrolysis; 6.3 per cent for E g= 2.4 eV for series voltage biased photoelectrolysis; and 4.7 per cent for E g= 2.2 eV for pH biased photoelectrolysis. For power cells with redox operation, type (a) oxides are predicted to give 5–6 per cent efficiency for E g= 2.4 eV, with a redox couple having standard potential not less than 0.8 V. High efficiency operation of photoelectrochemical cells with type (a) oxide anodes appears to be possible only in some special cases. Comparisons of the observed stabilities for a wide range of oxides with their calculated thermodynamic stabilities towards photoanodic dissolution indicate that oxygen overpotentials at the oxide anodes in photoelectrolysis may be small, and that the thermodynamic method of estimation of long term stability in oxide anodes is useful. The prospects of obtaining satisfactory efficiencies with oxides containing partly-filled d-levels are also examined, and found to be severely limited by the simultaneous requirements of stability, flat band potential, and band gap. Some suggestions for further research are made.