TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The solid-state p-n heterojunction is sensitized using sensitizing agent (B) comprising molecular and/or polymeric sensitizing agent, dye chosen from ruthenium complex dye, metal-phthalocyanine complex dye, metal-porphyrin complex dye, squaraine, thiophene-based dye, fluorine-based dye and polymer dye and p-type semiconductor material and/or n-type semiconductor material. The sensitizing agent (A) further comprises an insulating material having band gap of more than 3 eV, preferably more than 5 eV, more preferably 5-30 eV, metal nanoparticles which provide near-field enhancement of light-absorption by molecular or polymeric sensitizing agent(s) of sensitizing agent (B) and metal nanoparticles which provide near-field enhancement of light-absorption by p-type and/or n-type semiconducting materials. The p-type material is an organic hole-transporter, preferably optionally oligomerized, polymerized and/or cross-linked compound of formula: (R a) x-A-(R p) z(I), (R a-) x(R p-) z(A) v-n-(R) w(II), (III), (IV) and/or (V), preferably compound of formula (VI).n=1-20;A,A 1-A 4=mono- or polycyclic system comprising at least one pair of conjugated double bond (-C=C-C=C-), optionally substituted cyclic system optionally comprising heteroatoms;v=1-3;R w=optional residue chosen from optionally substituted 1-30C hydrocarbyl residue optionally comprising heteroatoms;w=0-2;v+w=3 or less;R a=linear, branched or cyclic alkyl or residue comprising oxygen atom(s) (both optionally substituted by halo);x=0 to maximum possible number of substituents of group (A);R p=optional residue enabling polymerization reaction with compounds (I-V);R=1-6C alkyl or 1-6C O-alkyl;(R a/p) x/z, (R" a/p) x/z, (L a/p) x/z, (L' a/p) x/z=R aor R p;andz=0, 1 or 2.R pmay be linked to N-atom, group (A) and/or substituent (Rp) of other structures repeatedly to form cross-linked and/or polymerized groups of compounds (I-V). Preferred Property: The coating thickness of sensitizing agent (A) is 1-100 nm. Preferred Process: The sensitizing agent (A) is distributed primarily at the surface of n-type semiconductor material. The sensitizing agent (A) is introduced within a mesoporous layer of n-type material, at the junction between the n-type material and the p-type hole transporter, between a compact layer of n-type material and a mesoporous layer of n-type material, within the hole transporter, between the anode and a compact layer of n-type material, and between the hole transporter and the cathode.