Molecular semiconductors: photoelectrical properties and solar cells

During the past thirty years considerable efforts have been made to design the synthesis and the study of molecular semiconductors. Molecular semiconductors - and more generally molecular materials - involve interactions between individual subunits which can be separately synthesized. Organic and metallo-organic derivatives are the basis of most of the molecular materials. A survey of the literature on molecular semiconductors leaves one rather confused. It does seem to be very difficult to correlate the molecular structure of these semiconductors with their experimental electrical properties. For inorganic materials a simple definition delimits a fairly homogeneous family. If an inorganic material has a conductivity intermediate between that of an 12 1 1 3 1 1 insulator « 10- n- cm- ) and that of a metal (> 10 n- cm- ), then it is a semiconductor and will exhibit the characteristic properties of this family, such as junction formation, photoconductivity, and the photovoltaic effect. For molecular compounds, such simplicity is certainly not the case. A huge number of molecular and macromolecular systems have been described which possess an intermediate conductivity. However, the various attempts which have been made to rationalize their properties have, more often than not, failed. Even very basic electrical properties such as the mechanism of the charge carrier formation or the nature and the density ofthe dopants are not known in detail. The study of molecular semiconductor junctions is very probably the most powerful approach to shed light on these problems

23-tól 30-ig Prolongálva! - Előadások kezdete 5 órától folytatólag

Szöveges plakát, melyet széles sávokban szecesziós keret határol. A mozi "Carmen" felirata egy szalagon olvasható. Fölötte filmtekercs kanyarog. A keretet sűrű növényi ornamentika, virágok és levelek alkotják. Színek: mustársárga, sötétkék és fekete, fehér

Revealing Gauguin: Engaging Visitors in Robot Guide’s Explanation of an Art Museum

Yamazaki K, Yamazaki A, Okada M, et al. Revealing Gauguin: Engaging Visitors in Robot Guide’s Explanation of an Art Museum. In: ACM Conference on Human Factors in Computing Systems. 2009: 1437-1446.Designing technologies that support the explanation of museum exhibits is a challenging domain. In this paper we develop an innovative approach - providing a robot guide with resources to engage visitors in an interaction about an art exhibit. We draw upon ethnographical fieldwork in an art museum, focusing on how tour guides interrelate talk and visual conduct, specifically how they ask questions of different kinds to engage and involve visitors in lengthy explanations of an exhibit. From this analysis we have developed a robot guide that can coordinate its utterances and body movement to monitor the responses of visitors to these. Detailed analysis of the interaction between the robot and visitors in an art museum suggests that such simple devices derived from the study of human interaction might be useful in engaging visitors in explanations of complex artifacts