Enhancing the short-circuit current, efficiency of inverted organic solar cells using tetra sulfonic copper phthalocyanine (TS-CuPc) as electron transporting layer

•Bulk-heterojunction polymer solar cells inverted configuration.•Enhanced performance of P3HT:PCBM based polymer solar cells without annealing.•Oxidized TS-CuPc as the electron collecting layer and MoO3 as hole collecting layer.

Efficient bulk-heterojunction polymer solar cells based on poly(3-hexylthiophene) (P3HT) blended with a fullerene derivative, [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) were fabricated in inverted configuration by using copper phthalocyanine-3,4′,4′′,4′′′tetra-sulfonated acid tetrasodium salt (TS-CuPc) as the electron collecting layer and MoO3 as hole collecting layer. TS-CuPc is observed to be critical for the device performance, significantly enhancing the Jsc and the PCE compared to devices based on TiOx. The optimal thicknesses of MoO3 and TS-CuPc were 10 nm and 15 nm, respectively. Based on these optimal parameters, the PCE of 3.6% was obtained compared to 3.4% for the reference TiOx/P3HT:PCBM/MoO3/Ag.

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