Photovoltaic cell sensitizers

Tennakone K., Kumara G., Wijayantha K., Kottegoda L, Perera V., Aponsu G. Nano-porous solid-state photovoltaic cell sensitized with tannin. Semicond. Sci. Technol. 1998 13 134-138 Tennakone K., Kumara G.R.R.A., Kottegoda I.R.M., Perera V.P.S. An efficient dye-sensitized photoelectrochemical solar cell made from oxides of tin and zinc. Chem. Commun. 1999 15-16... 

Gilot, J., Abbel, R., Lakhwani, G., Meijer, E.W., Schenning, A.P.H.J., Meskers, S.C.J. Polymer photovoltaic cells sensitive to the circular polarization of light. Adv. Mater. 22, E131-E134(2010)... 

Photovoltaic cells are independent of an electrical supply but, in general, they lack sensitivity as compared with photoemissive units. 

The theoretical solar conversion efficiency of a regenerative photovoltaic cell with a semiconductor photoelectrode therefore depends on the model used to describe the thermodynamic and kinetic energy losses. The CE values, which consider all the mentioned losses can generally only be estimated the full line in Fig. 5.65 represents such an approximation. Unfortunately, the materials possessing nearly the optimum absorption properties (Si, InP, and GaAs) are handicapped by their photocorrosion sensitivity and high price. 

Gratzel, M. (2005) Solar energy conversion by dye-sensitized photovoltaic cells. Inorganic Chemistry, 44 (20), 6841-6851. 

Apart from recapture of the injected electrons by the oxidized dye, there are additional loss channels in dye-sensitized solar cells, which involve reduction of triiodide ions in the electrolyte, resulting in dark currents. The Ti02 layer is an interconnected network of nanoparticles with a porous structure. The functionalized dyes penetrate through the porous network and adsorb over Ti02 the surface. However, if the pore size is too small for the dye to penetrate, that part of the surface may still be exposed to the redox mediator whose size is smaller than the dye. Under these circumstances, the redox mediator can collect the injected electron from the Ti02 conduction band, resulting in a dark current (Equation (6)), which can be measured from intensity-modulated experiments and the dark current of the photovoltaic cell. Such dark currents reduce the maximum cell voltage obtainable, and thereby the total efficiency. 

Adapted from M. Gratzel, Solar Energy Conversion by Dye-Sensitized Photovoltaic Cells , Inorganic Chemistry, Volume 44 (20), 2005 American Chemical Society... 

Luhman WA, Holmes RJ (2009) Enhanced exciton diffusion in an organic photovoltaic cell by energy transfer using a phosphorescent sensitizer. Appl Phys Lett 94 153304... 

Figure 17.38 Schematic of a solid-state dye-sensitized photovoltaic cell. Reprinted with permission from Ref. 75. Copyright 2002 American Chemical Society.

Photovoltaic performance of the DSSC is described as follows Figure 8 shows the external spectral response curve of the photocurrent for nanocrystalline Ti02 solar cells sensitized by N3 and black dyes with the I /If redox mediator, where the incident photon-to-current conversion efficiency (IPCE) is represented as a function of wavelength. IPCE is obtained by the following equation ... 

Figure 33. Dye (D) sensitized electrochemical photovoltaic cell based on a wide bandgap semiconductor. Reprinted from R. Memming, Semiconductor Electrochemistry, Wiley-VCH Verlag GmbH, Weinheim (2001). Copyright 2001 with permission from Wiley-VCH Verlag GmbH.

Light emitting electrochemical cells OLED Photovoltaic Ruthenium sensitizers... 

Research on the solid state dye-sensitized solar cells (DSC) has gained considerable momentum recently as this embodiment is attractive for realizing flexible photovoltaic cells in a roll-to-roll production. The spzro-OMeTAD has been the most successful p-type organic conductor (hole transport material) employed. Its work function is about 4.9 eV and the hole mobility 2 x 10-4 cm2 s x. A schematic diagram of the solid sate DSC with the structure of this hole conductor is shown in Fig. 19. Reported first in 1998, the con-... 

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