fotowiderstaende and photo elements with an elevated sensitivity in the short-wave spectral region

摘要

1,055,698. Photo-conductive material. FARBENFABRIKEN BAYER A.G. Nov. 17, 1964 [Nov. 22, 1963], No. 46783/64. Heading H1K. A photo-conductive element comprises a semi-conductive material in contact with at least one layer of a colourless binder containing 0À01 to 2 weight per cent of one or more fluorescent dyestuffs. The dyestuffs are sodium salicylate, 1p-sulphamidophenyl-3-p-Cl-phenyl pyrazoline, 3-[2SP11/SP-Cl-4SP11/SP-diethylamino-triazinyl- (6SP11/SP)-amino phenyl] coumarin, 3-phenyl-7-[2SP1/SP- Cl-41-diethylamino-triazinyl-(6SP1/SP)] coumarin, the condensation product of 1 mol of terephthalic aldehyde and 2 mols of ethyl cyanoacetate, 4 - amino - 1 : 8 - naphthal - p - xenylimide, 1 - phenyl - 3 - styrylpyrazoline, 2 : 2SP1/SP - dihydroxy - α - naphthaldazine, 2 : 2SP1 /SP- dioxybenzaldazine - salicylaldazine, the ethyl ester of meta - monoethyl aminophenol - phthalein hydrochloride, anthraphyrimide, the condensation products of 1 mol of perylene-tetracarboxylic acid and 2 mols of 4 : 5-dichloro-orthotoluidine and meta - diethylaminophenolphthalein hydrochloride and 3 : 9-perylene dicarboxylic acid di-isobutyl ester. The semiconductive materials may be Si, Se, or the chalkogenides of Cd or Zn. The binder may be an epoxy, polyester, silicone or alkyd resin, a resin of polyisocyanates and polyhydroxy compounds, cellulose acetate, acetobutyrate or ester, low melting glasses or enamels. If more than one layer of binder containing a fluorescent dyestuff is used, as exemplified, then they are arranged so that the dyestuff having its absorption maxima at the longest wavelength is next to the semi-conductor. It is also advantageous that the layers are arranged such that the refractive indices of the binders increases towards the semi-conductor lays. A multilayer element is preferably built up either by applying each layer freshly to the element after the preceding layer has hardened or by forming individual layers separately and then combining the layer with the preceding layer by using its binder as an adhesive.