TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: In the organic solar cell structure: the first electrode comprises the ECL, where a surface of ECL is modified with the dye; the second electrode comprises the HCL, where a surface of HCL is modified with the dye; and a surface of transparent conductor layer is modified with the dye, where the modified surface is a surface which is in contact with the photoactive layer. The transparent conductor comprises transparent conducting oxide (TCO), which is indium tin oxide. The first electrode comprises a transparent conductor and the second electrode comprises a high work function contact. The second electrode comprises the transparent conductor and the first electrode comprises a low work function contact. The organic solar cell structure: has an inverted organic photovoltaic (OPV) structure or a conventional (non-inverted) OPV structure; and is applied to a substrate. Preferred Process: The step (e) comprises an immersion of the product of step (a), (c) and/or (d) in the dye solution.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The dye is a compound having energy levels in the required range to form a cascade for the appropriate charge as it is transferred from the active layer to the electrode. The dye: comprises a binding group, redox center/chromophore, and organic interface groups, where the redox center/chromophore is a pi -conjugated unit or a metal surrounded by a conjugated unit or units; includes organometallic complexes, or metal free organic dyes including acridine dyes, anthraquinone dyes, arylmethane dyes, cyanine dyes, diazonium dyes, phthalocyanine dyes, quinone-imine dyes, thiazole dyes, xanthene dyes, fluorene dyes, fluorone dyes, rhodamine dyes, ruthenium bi-pyridyl complexes and related organometallic centers, porphyrins, phthalocyanines, coumarin, squarines, perylenes or oligomers of light-absorbing polymers; and is covalently bonded to the surface via a functional group including phosphonate, sulfonate, carboxylate, amide or silane. EXAMPLE - Substrate (glass) was cleaned by immersing the substrate in a sequence of solvents (acetone and isopropanol) in an ultrasonic bath. The transparent conducting oxide (TCO) (transparent conductor layer) was then deposited on the glass by a sputtering technique and patterned by a lithographic process (i.e. etching with acid, followed by masking of the required active areas with a photoresist). Then the electron collecting layer (ECL) (formed of metal oxides) was deposited by spin coating, spray pyrolysis, dip-coating, doctor blade or other appropriate solution based methods, where the solution was formed by sol-gel precursors or by nanoparticles of metal oxides. Then the first functionalization was performed by the attaching the dye directly onto the transparent conducting oxide (TCO) or onto the ECL, by immersing in a dilute solution of the dye, or by applying the dye solution by drop casting, dipping, spin coating, doctor blade or gravure. Then optionally, excess dye (not bonded to the TCO or ECL surface) was removed by a rinsing process. Then the photoactive layer (formed by a bilayer system of a donor material and the acceptor) was deposited by common solution processing methods (e.g. spin coating, dip coating or spray coating). Then the hole collecting layer (HCL) was (formed of poly(3,4-ethylenedioxythiophene) and poly(styrenesulfonate), or molybdenum oxide) was deposited with hole injection properties. Then the second functionalization was performed by soaking the molybdenum oxide with dye to modify the HCL surface. Then metallic top contact was (performed by a high work function metal including gold or silver used for the top electrode) deposited either by metal evaporation or using metal paint by spin coating, ink printing, spray or doctor blade, thus to obtain the organic solar cell structure.