Molecular photovoltaics that mimic photosynthesis

Abstract

Learning from the concepts used by green plants, we have developed a photovoltaic cell based on molecular light absorbers and mesoporous electrodes. The sensitized nanocrystalline injection solar cell employs organic dyes or transition-metal complexes for spectral sensitization of oxide semiconductors, such as TiO 2 , ZnO, SnO 2 , and Nb 2 O 5 . Mesoporous films of these materials are contacted with redox electrolytes, amorphous organic hole conductors, or conducting polymers, as well as inorganic semiconductors. Light harvesting occurs efficiently over the whole visible and near-IR range due to the very large internal surface area of the films. Judicious molecular engineering allows the photoinduced charge separation to occur quantitatively within femtoseconds. The certified overall power conversion efficiency of the new solar cell for standard air mass 1.5 solar radiation stands presently between 10 and 11. The lecture will highlight recent progress in the development of solar cells for practical use. Advancement in the understanding of the factors that govern photovoltaic performance, as well as improvement of cell components to increase further its conversion efficiency will be discussed.

Effect of Carbon Modification on the Electrical, Structural, and Optical Properties ofTiO2Electrodes and Their Performance in Labscale Dye-Sensitized Solar Cells

“…The higher magnification HRTEM clearly reveals that USP TiO 2 We can, therefore, speculate that USP is a more efficient technique for incorporating carbon uniformly in the TiO 2 matrix. On the other hand, such a large change in lattice spacing, compounded with the large distribution shown in Figure 4(b) cannot be entirely due to carbon doping.…”

“…But the most up-to-date chart has been released by the National Renewable Energy Laboratory [1]. Solar cell types displaying the highest efficiency figures are difficult to produce due to material processing costs such as in silicon and GaAs alloys or precursor toxicity such as in selenides and sulfides and hence expensive [2]. These disadvantages are not an issue in low efficient types such as the organic ones and the dye-sensitized cells.…”

Maximizing omnidirectional light harvesting in metal oxide hyperbranched array architectures

“…The as-prepared TiO 2 arrays showcase different geometry and porosity, and thus a different accessibility for dye adsorption. In order to qualify the area available for dye anchoring, the roughness factor measured by a N719 dye desorption method (as seen in Supplementary Table 3) [38][39] shows an increase of value from 516.0 to 1457.3 along with the continuously proceeded branched modification and thus indicating that the TNW-NS-NR hyperbranched arrays possess the largest surface area per unit volume for a given thickness for maximized dye uptakes. Hence, as seen in Table 1, dye loading amount of approximately twofold increase for TNW-NS (97.77 nmol cm À 2 ) and threefold increase for TNW-NS-NR (151.3 nmol cm À 2 ) can be observed as compared with the TNW scaffold (53.57 nmol cm À 2 ).…”

Approaches for biological and biomimetic energy conversion

“…Although it is very difficult to reproduce the dynamic physics of biological self-assembly outside of living systems, applying similar noncovalent chemistries and using traditional engineering methods to produce well ordered systems have been shown to be plausible methods for producing artificial photosynthesis (40,(48)(49)(50).…”