Photoelectrochemical semiconductor cell

Photoelectrochemical semiconductor cells are used to convert photon energy into chemical substances or into electricity, the former is a photodectrolytic cell and the latter is a photovoltaic cell. A photoelectrochemical semiconductor cell consists of either a pair of metal and semiconductor electrodes or a pair of two semiconductor electrodes. 

Bard AJ, Wrighton MS (1977) Thermodynamic potential forthe anodic dissolution of n-type semiconductors - A crucial factor controlling durability and efficiency in photoelectrochem-ical cells and an important criterion in the selection of new electrode/electrolyte systems. J Electrochem Soc 124 1706-1710... 

Pandey RN, Misra M, Srivastava ON (1998) Solar hydrogen production using semiconductor septum (n-CdSe/n and n-U02/Ti) electrode based photoelectrochemical solar cells. Int J Hydrogen Energy 23 861-865... 

Chandra Babu KS, Pandey RN, Srivastava ON (1995) Photoelectrochemical semiconductor septum (CdSe/Ti and Ti02/Ti) solar cells in relation to hydrogen production. Int J Hydrogen Energy 20 771-775... 

Space charge layers and contact potential for efficient charge carrier separation can be achieved with proper semiconductor structure in several ways. When possible semiconductor structures are considered, the charge separation can be attained in an active mode, i.e., by the use of a potential bias in a photoelectrochem-ical cell, or in a passive mode, i.e., with the use of proper contact between different phases. 

Study of the Potential Distribution at the Semiconductor-Electrolyte Interface in Regenerative Photoelectrochemical Solar Cells... 

The electronic properties of semiconductors junctions are strongly dependent on their interfaces. This is especially true for semiconductor/electrolyte contacts as in photoelectrochemical solar cells, for which a variety of possible reactants must be considered. 

In this paper our results to simulate the photoactive semiconductor/ electrolyte interface in UHV by adsorbing halogens and H20 on semiconductor surfaces are described. For these experiments layer type compounds and ternary chalcogenides have been considered because clean faces can easily be prepared by cleaving the crystals in UHV and because the reactions with halogens are intensively studied for photoelectrochemical solar cells. 

As will be shown in Section 2.4, these observations have a large impetus on the performance of photoelectrochemical solar cells. It should also be mentioned the reverse processes, here the oxidation of the redox system, does not necessarily also occur via the conduction band. Since the reorganisation energies are typically in the range of A, = 0.5-1.2 eV, the oxidation of the redox couple may occur via the valence band, especially for semiconductors of a bandgap smaller than 2 eV. 

SEMICONDUCTOR/LIQUID JUNCTION PHOTOELECTROCHEMICAL SOLAR CELLS... 

Semiconductor/Liquid Junction Photoelectrochemical Solar Cells... 

Semiconductor/Liquid Junction Photoelectrochemical Solar Cells 9.4 Chemical modification of semiconductor surfaces... 

Assuming a quantum efficiency of unity, then /e is the photocurrent of the cell. The maximum conversion efficiency is defined by Eq. (11.5). It can be calculated for semiconductors of different bandgaps from Eqs. (11.5) and (11.12). The results are presented in Fig. 11.9. The highest efficiency is 28 % at g = 1.2 eV. This calculation is valid for solid state photovoltaic devices (p-n junction, Schottky junction) as well as for a photoelectrochemical photovoltaic cell. 

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