TECHNOLOGY FOCUS - IMAGING AND COMMUNICATION - Preferred Components: The dye has an absorption with a decadic absorbance of at least 0.1, at a wavelength in a spectral range of above ( lambda (HTL)). The matrix material comprises at least one varnish, which is a polyacrylate-polyester varnish. The varnish is applied by applying a coating composition, and where the coating composition comprises at least one polyester resin (A), at least one polyacrylate resin (B1) and preferably at least one crosslinking agent, which is polyisocyanates (preferred), amide- and amine-formaldehyde resins, phenol resins, aldehyde resins or ketone resins. The varnish comprises at least one organic matrix material and at least one, preferably at least two absorber material introduced into the matrix material.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The ( lambda (HTL)) is less than or equal to 440 nm. The absorption spectrum of the organic hole conductor material at a wavelength of ( lambda (HTL))+30 nm has declined to a decadic absorbance of less than 0.2 and for wavelengths of (~(HTL))+30 nm to 800 nm has a decadic absorbance of less than 0.2. The longpass filter has an edge steepness (S(LP)) of the rising transmission edge, where (S(LP) is less than or equal to 1.2 eV. The photovoltaic element has a transparent substrate (114), the longpass filter having been applied to the transparent substrate. The first electrode or the second electrode have been applied to a first side of the substrate, the longpass filter having been applied to a second side of the substrate opposing the first side. The longpass filter in at least one transmission region takes up a transmission of at least 75%. The longpass filter in at least one absorption region takes up a decadic absorbance of at least 3. The organic hole conductor material is or comprises an arylamine compound and/or a spiro compounds of formula (I), preferably 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene. The organic hole conductor material is or comprises substituted methyl-diphenyl-amine compounds of formula (II). The longpass filter comprises at least two absorber materials introduced, especially mixed, into the matrix material, one absorber material is an absorber material comprising a triazine group, preferably an absorber material having the a substituted 2,4-bis-(2,4-dimethyl-phenyl)-6-phenyl-(1,3,5)triazine compounds of formula (III), and the other absorber material is a substituted 2-(2-hydroxy-phenyl)-2H-pyrrolo(3',4':4,5)benzo(1,2-d)(1,2,3)triazole-5,7-dione compounds of formula (IV). The longpass filter comprises: at least one organic filter dye, preferably rylene dye; at least one inorganic filter material, preferably an inorganic filter material consisting of silicon dioxide, titanium dioxide, zirconium dioxide or tantalum oxide; and at least one transparent organic matrix material and at least one absorber material introduced into the matrix material.aryl1-aryl8 = substituted aryl or heteroaryl, preferably substituted phenyl (all substituted by at least one substituents consisting of -O-alkyl, -OH, -F, -Cl, -Br or -I), where alkyl is preferably methyl, ethyl, propyl or isopropyl, the phenyl radicals are substituted by at least one substituents of -O-Me, -OH, -F, -Cl, -Br or -I;A1-A3 = optionally substituted aryl or heteroaryl;R1-R3 = substituents -R, -OR, -NR2, -A4-OR or -A4-NR2;R = alkyl, aryl or heteroaryl;A4 = aryl or heteroaryl;n = 0-3;alkylT = linear alkyl, preferably 12-13C alkyl;Rbb, Rbd = H, -alkyl, -OH, -alkylaryl, -alkylheteryl, -cycloalkyl, cycloheteroalkyl, alkenyl, aryl or -SO3H; andRxz = H, alkyl, aryl, heteroaryl, alkylaryl, alkylheteroryl, alkenyl or alkynyl.Provided that the sum of the individual values n is at least 2 and at least two of the R1, R2 and R3 are -OR and/or -NR2. Preferred Process: The longpass filter is producible by a sol-gel process. The longpass filter is producible by applying a solution comprising at least one filter material and at least one solvent to a substrate, and then the solvent is removed. The longpass filter is produced by introducing at least one absorber material into at least one transparent organic matrix material.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The absorber material comprises at least one organic absorber material. The organic absorber material is compounds comprising a benzotriazole group or a triazine group. EXAMPLE - As the base material and substrate, glass plates which had been coated with fluorine-doped tin oxide (FTO) as the first electrode (working electrode) and were of dimensions 25x 25x 3 mm (Hartford Glass) were used, which were treated successively in an ultrasound bath with glass cleaner, demineralized water and acetone, for 5 minutes in each case, then boiled in isopropanol for 10 minutes and dried in a nitrogen stream. To produce an optional solid titanium oxide buffer layer, a spray pyrolysis process was used. A titanium oxide paste (Dyesol) (as an n-semiconductive metal oxide) which comprises titanium oxide particles with a diameter of 25 nm in a terpineol/ethylcellulose dispersion was spun on with a spin-coater at 4500 rpm and dried at 90 degrees C for 30 minutes. After heating to 450 degrees C for 45 minutes and a sintering step at 450 degrees C for 30 minutes, a titanium oxide layer thickness of approximately 1.8 mu m was obtained. After removal from the drying cabinet, the sample was cooled to 80 degrees C and immersed into an optional 5 mM solution of an additive ID662 (sodium 2-(4-butoxy-phenyl)-N-hydroxy-acetamide) for 12 hours and subsequently into a 0.5 mM solution of a dye in dichloromethane for 1 hour. After removal from the solution, the sample was subsequently rinsed with the same solvent and dried in a nitrogen stream. The samples obtained in this way were subsequently dried at 40 degrees C under reduced pressure. Next, a solution of an organic p-semiconductor was spun on. For this purpose, a solution of 0.163M 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-MeOTAD) and 20 mM lithium bistrifluoromethane sulfoneimide in chlorobenzene was made up. The solution (125 mu l) were applied to the sample and allowed to act for 60 seconds. Then, the supernatant solution was spun off at 2000 rpm for 30 seconds. Finally, a metal back electrode was applied as a second electrode by thermal metal vaporization under reduced pressure. The metal used was silver, which was vaporized to give a layer thickness of 200 nm. The photovoltaic element was provided with longpass filter (commercially available glass longpass filters of the LCGG-X-2X2 type) on the non-FTO-coated side of the glass substrate.