Organic Polyaromatic Hydrocarbons as Sensitizing Model Dyes for Semiconductor Nanoparticles

Abstract

The study of interfacial charge-transfer processes (sensitization) of a dye bound to large-bandgap nanostructured metal oxide semiconductors, including TiO(2), ZnO, and SnO(2), is continuing to attract interest in various areas of renewable energy, especially for the development of dye-sensitized solar cells (DSSCs). The scope of this Review is to describe how selected model sensitizers prepared from organic polyaromatic hydrocarbons have been used over the past 15 years to elucidate, through a variety of techniques, fundamental aspects of heterogeneous charge transfer at the surface of a semiconductor. This Review does not focus on the most recent or efficient dyes, but rather on how model dyes prepared from aromatic hydrocarbons have been used, over time, in key fundamental studies of heterogeneous charge transfer. In particular, we describe model chromophores prepared from anthracene, pyrene, perylene, and azulene. As the level of complexity of the model dye-bridge-anchor group compounds has increased, the understanding of some aspects of very complex charge transfer events has improved. The knowledge acquired from the study of the described model dyes is of importance not only for DSSC development but also to other fields of science for which electronic processes at the molecule/semiconductor interface are relevant.

Metal-free hydrogenation catalysis of polycyclic aromatic hydrocarbons

“…Polycyclic aromatic hydrocarbons (PAHs) are potent atmospheric pollutants generated by fuel combustion 1 but they also occur naturally in oil, coal, and tar deposits as well as in comets and meteorites. 2 While these compounds are found in grilled meats or smoked fish and are known to exhibit carcinogenic, mutagenic, and teratogenic effects, [3][4][5][6][7][8] these polyaromatic compounds are also finding applications in energy storage, 9 photosensitizers 10 for solar cells and electronic devices. 11 Partial hydrogenation of PAHs has been achieved by employing Birch reductions, LiAlH 4 [12][13][14][15][16][17] or transition metal-based catalysts [18][19][20][21][22] and this can be exploited as a strategy for ''protection''.…”

Synthesis and functionalization study of hierarchical ZnO nanowires for potential nitroaromatic sensing applications

“…Since a carboxylic acid (-COOH) moiety is known to form covalent linkages onto metal oxides [25], it is pertinent to investigate the effect of a long chain carboxylic acid (-COOH) compound on our as-synthesized ZnO nanowires. Oleic acid was appropriate choice for this investigation due to its excellent surfactant properties as well as the potential for it to be reversibly replaced by pyrenebutyric acid (PBA) in a metal oxide nanoparticle solution [26].…”

New [4]helicene derivatives: Synthesis, characterization and photophysical properties

“…Owing to their specific structure and photoelectric properties, polycyclic aromatic hydrocarbons (PAHs) have led also to applications in electronic devices. They have proven to be one of the most important semiconductors [4][5][6][7]. Acenes, for example, represent highly attractive compounds with good performance as semiconductors and good emission properties, and they have been widely used in various fields, such as inorganic field-effect transistors [8][9], organic light-emitting diodes (OLEDs) [10] and organic photovoltaics [11][12].…”