PECS cells

Simple electroless techniques have been used for the formation of CdTe layers following an anodic or a cathodic route of deposition. For instance, spontaneous cathodic formation of CdTe was observed on Ti or glass electrodes short circuited with a corroding A1 contact (electron source) in a solution of Cd " " and HTe02 ions [96]. After thermal treatment and subsequent growth of an a-Pb02 layer on them, the as-obtained CdTe thin films were found to exhibit n-type behavior in alkaline polysulfide PEC cells. 

MV /MV " (HV is heptyl viologen and MV is methyl viologen). The specific effects of iodide on the electrochemical behavior of the layer-type compounds were compared, and the characteristics of several PEC cells were described. The interface energies for n-MoSe2 in contact with various redox couples were given as in Fig. 5.9. 

Miller DJ, Haneman D (1981) Preparation of stable efficient CdSe films for solar PEC cells. Sol Energy Mater 4 223-231... 

PEC cell that uses polycrystalline thin-film solar cells with a photoanode. 

The same authors also discussed the optimal design of a photo-electrochemical (PEC) cell using C-doped Ti02 nanotube arrays as the photoanode and Pt nanoparticles incorporated in Ti02 nanotube arrays as... 

A large number of studies on CD have been driven by two related potential uses photoelectrochemical (PEC) cells, mostly the earlier studies, and, more recently, photovoltaic (PV) cells. This chapter is devoted to these two topics where CD films have been used. 

Ti02 has three crystal forms, anatase, brookite, and rutile. Rutile is a stable form, and the others are a low-temperature form. The band gap energy of rutile is ca. 3.0 eV, while those of the other two are ca. 3.2 eV. Since an external bias was required for the photoelectrolysis of water in a Ti02(rutile)-Pt PEC cell,1 one may assume that rutile powder shows no activity for the photocatalytic decomposition of water. Yamaguti and Sato,3) found that platinized rutile Ti02 powder is active... 

Most detailed studies of water photodissociation on SrTi03 and Ti02 have concentrated on photoelectrochemical cells (PEC cells) operating under conditions of optimum efficiency, that is with an external potential applied between the photoanode and counterelectrode. We have become interested in understanding and improving reaction kinetics under conditions of zero applied potential. Operation at zero applied potential permits simpler electrode configurations (11) and is essential to the development of photochemistry at the gas-semiconductor interface. Reactions at the gas-sold, rather than liquid-solid, interface might permit the use of materials which photocorrode in aqueous electrolyte. 

Figure 8. Simultaneous measurements of Hs yield and integrated current passed as a function of NaOH electrolyte concentration for a n-SrTiOs/Pt PEC cell ((left) gas chromatography ("right,) coulometry). Each vertical division corresponds to the equivalent of 5000 monolayers Ht produced. ((A) 0.01 F (O) 1 F (SJ) 10 F ...

We have been studying silicon as a PEC cell, partly because silicon would be an exceptionally valuable material for solar cells if the corrosion could be controlled, and partly because the corrosion product, Si02, has particularly simple characteristics it is generally insoluble in aqueous solutions, and it... 

Fig. 3.1. A photoelectrochemical (PEC) cell for photo assisted water splitting.

It is generally accepted that three major processes limit the photoelectrochemical current in semiconductors after a bandgap excitation [76]. These processes are schematically illustrated in the band diagram shown in Fig. 3.2. The bold arrows show the desired processes for efficient water splitting PEC cell after a bandgap excitation the transport of electrons to the back contact, the transfer of the hole to the semiconductor surface and the oxidation of water at the semiconductor/electrolyte interface. The three major limiting processes are a) bulk recombination via bandgap states, or b) directly electron loss to holes in the... 

Two sources of n-Si wafers, coated with 3.7-6.6 nm layers of SiOxNy ( y), were used with comparable results. From Auger analysis, it follows that upon using these materials as photoanodes in wet PEC cells, the already low photocurrents (of the order of 10 8 A/cm2) decrease upon operation by oxidation of the coated electrode, whereby x increases at the exoense of y and by oxidation of Si. The starting SiOxNy layers already have avery high resistance (1.9. l o13 fi.cm- ). This resistivity must be diminished for more efficient operation. Two routes have been followed ... 

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