NOVELTY - An optoelectronic apparatus comprises active layer (100) containing a nanostructured network layer (102) having network of regularly spaced structures with spaces between neighboring structures, where the structures are interconnected; at least one network-filling materials disposed in the spaces; an interfacial layer (108) disposed between the nanostructured network layer and network-filling material; where the interfacial layer includes at least one selected from acid-, ester-, amide-, amine-, or other-functionalized fullerene, or functionalized carbon nanotubes.    USE - As optoelectronic apparatus (claimed) e.g. PV cells, solar cells.    ADVANTAGE - The optoelectronic apparatus using the interfacial layer, which provide charge transfer between the two materials that exhibits different rates for forward versus backward transport; differential light absorption to extend a range of wavelengths that the active layer can absorb; enhances light absorption, which is coupled with charge injection. The optoelectronic apparatus is cost effective.    DETAILED DESCRIPTION - An optoelectronic apparatus comprises an active layer (100) containing a nanostructured network layer (102) having network of regularly spaced structures with spaces between neighboring structures, where the structures are interconnected and interconnections between structures comprise of a material that is the same as a material used to form the structures; at least one network-filling materials disposed in the spaces, where network-filling material has complementary charge transfer properties with respect to the material of the nanostructured layer; an interfacial layer (108) disposed between the nanostructured network layer and network-filling material, where the interfacial layer is configured to enhance an efficiency of the apparatus; where the interfacial layer includes at least one selected from an acid-, ester-, amide-, amine-, or other-functionalized fullerene, or functionalized carbon nanotubes. The interfacial layer includes functionalized C60, (6,6)-phenyl C61-butyric acid methyl ester (PCBM), C60, C70, C76, C84 or other functionalized fullerenes in mono-adduct or dual-adduct mode.    DESCRIPTION OF DRAWING(S) - The figure shows active layer for an optoelectronic device.    Active layer (100)    Nanostructured network layer (102)    Network filling materials (104, 106)    Interface layer (108)