Photovoltaic performance of solution-processed ternary solar cells based on PTB7: PCBM and squaraine dye

Abstract

The performance of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl] [3-fluoro-2-[(2-ethylhexyl)carbonyl] thieno[3,4-b]thiophenediyl]]: [6,6]-phenyl-C70-butyric-acid-methyl-ester) (PTB7: PC70BM) based inverted bulk heterojunction organic solar cell by introducing squaraine (SQ) dye as the third component is investigated. The photovoltaic devices with an architecture ITO/ ZnO/ active layer/ MoO3 /Ag in which active layers of pristine PTB7: PCBM, and PTB7: PCBM: SQ with different concentrations of SQ are fabricated, and the J-V characteristics are measured under an illumination intensity of 100 mWcm−2. The effect of the introduction of SQ on the photovoltaic parameters of PTB7: PCBM solar cells are analyzed in detail. UV-Vis-NIR absorption spectra of the binary and ternary blends are recorded to study the variations in the absorption with different loadings of SQ in the ternary blends. The morphology of the blend films is analyzed by atomic force microscopy. To study the influence of device area on the cell parameters, solar cells of different active areas viz. 0.09, 0.25, 0.49, and 1 cm2 are made and the variation of cell parameters like short circuit current density, open circuit voltage and fill factor with device area is also studied.The performance of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl] [3-fluoro-2-[(2-ethylhexyl)carbonyl] thieno[3,4-b]thiophenediyl]]: [6,6]-phenyl-C70-butyric-acid-methyl-ester) (PTB7: PC70BM) based inverted bulk heterojunction organic solar cell by introducing squaraine (SQ) dye as the third component is investigated. The photovoltaic devices with an architecture ITO/ ZnO/ active layer/ MoO3 /Ag in which active layers of pristine PTB7: PCBM, and PTB7: PCBM: SQ with different concentrations of SQ are fabricated, and the J-V characteristics are measured under an illumination intensity of 100 mWcm−2. The effect of the introduction of SQ on the photovoltaic parameters of PTB7: PCBM solar cells are analyzed in detail. UV-Vis-NIR absorption spectra of the binary and ternary blends are recorded to study the variations in the absorption with different loadings of SQ in the ternary blends. The morphology of the blend films is analyzed by atomic force microscopy. To study the influence of ...