Large absorption coefficients

For the three oclyloxy-subslitulcd five-ring oligomers, the normalized photoluminescence spectra of the single crystals are depicted in Figure 16-26. Due to the large absorption coefficient (more than 105 cm"1 at the maximum) we were not able to measure the absorption spectra of the relatively thick (20-30 pm) single crystals (see Table 16-5 in Section 16.3.3.3.1). 

Abstract Silver clusters, composed of only a few silver atoms, have remarkable optical properties based on electronic transitions between quantized energy levels. They have large absorption coefficients and fluorescence quantum yields, in common with conventional fluorescent markers. But importantly, silver clusters have an attractive set of features, including subnanometer size, nontoxicity and photostability, which makes them competitive as fluorescent markers compared with organic dye molecules and semiconductor quantum dots. In this chapter, we review the synthesis and properties of fluorescent silver clusters, and their application as bio-labels and molecular sensors. Silver clusters may have a bright future as luminescent probes for labeling and sensing applications. 

Large absorption coefficients and high reduction potentials (highly absorbent and oxidizing)... 

CuInSi (and, even more, CuInSei) are strong candidates for thin-film photovoltaic cells. For this purpose, the chalcopyrite structure (which is an ordered lattice) is preferred over the disordered, zincblende form. Due to the large absorption coefficients of these materials, a 1-iJim-thick film is more than enough to absorb almost all the suprabandgap radiation. Somewhat thicker films are generally used, due to problems of pinholes, which commonly occur in thinner films. A number of methods have been used to deposit these films. Surprisingly, very few (published) attempts have been made to deposit them by CD. 

They have large absorption coefficients due to allowed tt-tt transitions. 

Excited states of N20, undergoing reactions (50), (51), and (52), are all triplets, transitions to which are spin forbidden. A large absorption coefficient (e = 200) at this wavelength appears to eliminate these processes, but it is possible that these triplet states may interact with neighboring singlet states which makes an intercombination possible.74... 

The terpyridine-substituted difluoroborondipyrromethene dye 88 is a singlet emitter at 540 nm (18 500 cm ) and its triplet state emission extends from 550-750 nm (18200-13 300 cm ), which makes it a potential sensitizer of lanthanide NIR luminescence. In [Yb(N03)3(88)] (see fig. 75), the lanthanide ion is bound to the terdentate terpyridine and to three bidentate nitrate counterions, in a distorted tricapped antiprismatic geometry. The Ln complexes (Ln = La, Nd, Er, Yb) have large absorption coefficients (65 000 cm ... 

It has been shown that, upon doping, three new bands appear in the infrared, with such a very large absorption coefficient that, even for weak doping, they dominate the whole IR spectrum [34,35]. The doping-induced bands show the following characteristics in the frequencies Vj and the intensities... 

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