Performance enhancement of dye-sensitized solar cells via co-sensitization of ruthenium (II) based N749 dye and organic sensitizer RK1

• Published in: Solar energy Vol. 203; pp. 260 - 266
• Main Authors: Younas, M., Harrabi, K.
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 01-06-2020; Pergamon Press Inc
• Subjects: Co-sensitization; Current voltage characteristics; DSSC; Dye-sensitized solar cells; Dyes; Efficiency; Electrochemical impedance spectroscopy; Electrochemistry; Electron recombination; Energy conversion efficiency; Organic Sensitizer (RK1); Performance enhancement; Photovoltaic; Photovoltaic cells; Photovoltaics; Recombination; Ruthenium; Ruthenium (II) based dye (N749); Solar cells; Solar energy; Spectroscopy; Spectrum analysis; Organic Sensitizer (RK1); Photovoltaic; Ruthenium (II) based dye (N749); Co-sensitization; Efficiency; DSSC
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2020.04.051

[Display omitted]
•DSSC performance is improved using co-sensitization approach.•Organic sensitizer RK1 is used as the co-sensitizer with ruthenium (II) based N749 dye.•Five solutions of mixed dyes with two solutions of individual dyes are used.•The DSSC are characterized using UV–Vis, I-V, IPCE and EIS analysis.•The absorption increases with higher RK1 contents.•Peaks also become more intense and broader when dyes anchored to the TiO2.
The aim of the reported study is to enhance the photovoltaic performance of a dye-sensitized solar cells (DSSCs) using co-sensitization approach and investigate how the concentration of an organic co-sensitizer influence the overall efficiency of the fabricated DSSCs. The overall efficiency of the fabricated DSSC with co-sensitization approach using a ruthenium (II) based dye, N749, and an organic sensitizer, RK1, is 8.15%. The solar cells were evaluated using UV–Vis spectroscopy, electrochemical impedance spectroscopy (EIS), incident photon to electron conversion efficiency (IPCE), and current-voltage (I-V) characteristics. The concentration of the organic co-sensitizer has a strong effect on the performance of the DSSC. An optimized solar cell fabricated with a dye solution of 0.2 mM RK1 and 0.3 mM N749 yielded a Jsc (mA/cm2) = 19.45, Voc (mV) = 688, FF (%) = 61 and power conversion efficiency (PCE) of η(%) = 8.15 under standard (AM1.5 G) 1 sun illumination (100 mW/cm2). The efficiency of co-sensitized DSSCs is far better than the efficiency of fabricated solar cells sensitized with individual dyes [N749 (η = 4.94%) and RK1 (η = 5.76%)]. The efficiency enhancement is due to the lower rate of recombination of electrons and holes, decreased I−/I−3 competitive absorption, and lower aggregation of the dyes resulting from the synergistic action in the co-sensitized photovoltaic cells.