Enhanced device efficiency of bilayered inverted organic solar cells based on photocurable P3HTs with a light-harvesting ZnO nanorod array

Periodically patterned zinc oxide nanorod (P-ZnO NR) layers are directly prepared from a pre-patterned ZnO seed layer using a polydimethylsiloxane (PDMS) elastomeric stamp and then applied in inverted organic photovoltaic devices (IOPVs). The IOPV is assembled with a hydrothermally grown zinc oxide nanorod patterns with a (100) preferential crystal orientation as an electron transport buffer layer (ETBL) and photoactive bilayer consisting of methacylate end-functionalized poly(3-hexylthiophene) (P3HT-MA), phenyl-C ₆₀-butyric acid methyl ester (PC₆₀BM) and indene-C ₆₀ bis-adduct (IC₆₀BA). In te IOPVs, the P-ZnO NR is found to induce efficient light harvesting and the photocrosslinkable P3HTs afford solution-processed bilayer architecture in IOPVs to show improved device stability and performance (PCE_max= 5.95%), as the bilayered structure allowed direct exciton splitting, thus reducing the charge recombination. Zinc oxide nanorods (P-ZnO NR) are patterned and applied in inverted organic photovoltaic devices (IOPV) as an electron transport buffer layer (ETBL) for the light harvesting effect. A 16% increase in device performance and long operational stability is observed resulting from the introduction of a periodically patterned zinc oxide nanorod layer, and the formation of photoactive layer consisting of photo-crosslinkable methacylate end-functionalized poly(3-hexyl thiophene) (P3HT-MA) and phenyl-C ₆₀-butyric acid methyl ester (PC₆₀BM) with indene-C ₆₀ bis-adduct (IC₆₀BA).