Wavelength sensitivity

Although silver iodide is the least photosensitive of the three halides, it has the broadest wavelength sensitivity in the visible spectmm. This feature makes silver iodide particularly useful in the photographic industry. It resists reduction by metals, but is reduced quantitatively by zinc and iron in the presence of sulfuric acid. 

The development of new classes of cationic photoinitiators has played a critical role in the production of highly sensitive, acid-catalyzed deep-uv photoresists. Sulfonium salts have been widely used in this respect (4). These materials are relatively easy to prepare and structural modifications can be used to produce desired wavelength sensitivity. Triphenylsulfonium salts are particularly well suited for deep-uv application and in addition can be photosensitized for longer wavelength. These salts are quite stable thermally and certain ones such as the hexafluoroantimonate salt are soluble in casting solvents and thus easily incorporated within resist materials. 

Although AS and AES can be detected at a low UV wavelength, sensitivity is lacking and a more suitable detection was achieved using indirect photometric detection, post-column colour formation reactions, or a pre-column derivatisation, suppressed conductivity detection and refractive index detection [1,42,43]. A comparison of detection limits for the determination of these anionic surfactants shows that photometric and conductivity detectors are better (picomole or nanogram range) than refractive index or fluorometry detectors by about a factor of 1000 [40],... 

In the presence of photoinduced proton transfer, the steady-state fluorescence intensities are given by Eqs (4.55) and (4.56). In the absence of deprotoration (i.e. in a very acidic solution such that k i [H30+] 1/tq), when the experimental conditions (concentrations, excitation and observation wavelengths, sensitivity of the instrument) are kept strictly identical, the fluorescence intensities is (Iah )o = C o- Rewriting Eqs (4.55) as fAH = C , the following ratio is obtained... 

Inaccurate temperature Unstable temperature Incorrect slit Broken cartridge Inaccurate voltage Unstable voltage Inaccurate current Unstable current Inaccurate wavelength Sensitivity problem Noise... 

Photo diode array Inaccurate wavelength Sensitivity and linearity problems. 

Farquhar J, Savarino J, Airieau S, Thiemens M (2001) Observation of wavelength sensitive mass independent sulfur isotope effects during SO2 photolysis Applications to the early atmosphere. J Geophys Res Planets 12 32829-32839... 

Wang, X. H. Li, J.-G. Kamiyama, H. Moriyoshi, Y ishigaki, T. Wavelength-Sensitive Photocatalytic Degradation of Methyl Orange in Aqueous Suspension... 

Dadabhoy, A. Faulkner, S. Sammes, P. G. Long wavelength sensitizers for europium(III) luminescence based on acridone derivatives. J. Chem. Soc., Perkin Trans. 22002, (2), 348-357. 

Because fluorescent objects are essentially self-luminous and viewed against a dark background, both the resolution and sensitivity are maximized. Resolution is maximized because the objects essentially emit light, often at relatively short wavelengths. Sensitivity is... 

A multicolour imager in which detectors having different wavelength sensitivities are stacked in a piggy-back fashion on top of one another and in which thin film interconnectors are used to connect the detectors with an integrated circuit, forming the detector substrate, is presented in US-A-4137625. 

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