Photoelectrochemical cells conversion efficiency

Nakato, Y., Ueda, K., Yano, H., and Tsubomura, H., Effect of microscopic discontinuity of metal over layers on the photo voltages in metal-coated semiconductor-liquid junction photoelectrochemical cells for efficient solar energy conversion, /. Phys. Chem., 92, 2316, 1988. 

Heller A, Chang KC, Miller B (1977) Spectral response and efficiency relations in semiconductor liquid junction solar cells. J Electrochem Soc 124 697-700 Elhs AB, Kaiser SW, Wrighton MS (1976) Optical to electrical energy conversion. Characterization of cadmium sulfide and cadmium selenide based photoelectrochemical cells. J Am Chem Soc 98 6855-6866... 

Schneemeyer LF, Wrighton MS (1980) n-Type molybdenum diselenide-based photoelectrochemical cells Evidence for Fermi level pinning and comparison of the efficiency for conversion of light to electricity with various solvent/halogen/halide combinations. J Am Chem Soc 102 6964-6971... 

The performances of the photoelectrochemical cells are strongly dependent on the composition of the electrolyte solution (Fig. 17.22). A maximum conversion efficiency of ca. 80%, in correspondence to the metal-to-ligand charge transfer absorption maximum of N3 was obtained in the presence of 0.25 M LiI/0.025 MI2, whereas with the cobalt-based mediators, the best performances (ca. 50-55% of IPCE) were observed when solutions of Co(DTB)32+/3+ and Co(tTBterpy)22+/3 + were used. In the other investigated cases, Co(phen)32 1 /3 1, Co(tEterpy)22+/3 +, and... 

It is known that the photoelectrochemical cell (PEC), which is composed of a photoelectrode, a redox electrolyte, and a counter electrode, shows a solar light-to-current conversion efficiency of more than 10%. However, photoelectrodes such as n- and p-Si, n-and p-GaAs, n- and p-InP, and n-CdS frequently cause photocorrosion in the electrolyte solution under irradiation. This results in a poor cell stability therefore, many efforts have been made worldwide to develop a more stable PEC. 

The heterojunctions of the polyacetylene were realized not only with inorganic photoconductors but also with organic polymers [139]. The results obtained show good similarity with barrier and heterojunction characteristics for inorganic semiconductors. Photoelectrochemical cell for solar energy conversion with polyacetylene electrodes and Na2S, electrolyte had an efficiency of 1 % at 2.4 eV [140], The complicated phenomena take place at the electrodeelectrolyte interface. 

In addition to yielding information about semiconductor charge-transfer dynamics, the fill factor parameterizes the efficiency with which the photo-electrochemical cell can be expected to convert optical energy to electricity. The practical value of a photoelectrochemical cell is usually evaluated by its maximum conversion efficiency. The energy conversion efficiency is defined as... 

Cd-chalcogenides (CdS, CdSe, CdTe) are among the most studied materials as photoelectrodes in a photoelectrochemical cell (PEC) (1,2 /3,4). Interest in such PEC s stems from the fact that, in aqueous polysulfide or polyselenide solutions, a drastic decrease in photocorrosion is observed, as compared to other aqueous solutions, while reasonable conversion efficiencies can be attained. 

Recently we showed that PEC s using alloys of Cd(Se,Te) as photoelectrodes can be prepared with stability characteristics much better than those obtained for CdTe based cells and with similar conversion efficiences (). Those efficiencies could be improved considerably by several chemical and photoelectrochemical surface treatments. 

Photosynthesis, another potential target of bioconjugation, is one of the most important processes in nature. In photosynthesis, photoelectric conversion with nearly 100% efficiency is involved in the primary process.47-48 Such a high performance of photosystem I (PSI) is due to its well-designed spatial configuration. A large number of trials have applied such biological systems to electronic devices. For example, chloroplasts coated on an SnC>2 electrode have been examined as photoelectrochemical cells.49-53... 

The first report of direct photoconversion of water into dihydrogen and dioxygen was studied on Ti02 (n-type) electrodes by Fujishima and Honda [64]. Although the overall efficiency of the system was low, their results initiated the interest in photoelectrochemical cells for conversion of solar energy to chemical energy (or to electrical energy). 

Another interesting attempt worth noting is the combination of porphyrin sensitized solar cell with a fuel cell made by Moore and Gust. The hybrid cell can realize an open circuit voltage of 1.2 V. The energy conversion efficiency of this photoelectrochemical biofuel cell can, in principle, produce more power than either a photoelectrochemical cell or a biofuel cell working individually [83],... 

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