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Influence of electrolyte co-additives on the performance of dye-sensitized solar cells.

Stergiopoulos T, Rozi E, Karagianni CS, Falaras P - Nanoscale Res Lett (2011)

Bottom Line: The presence of specific chemical additives in the redox electrolyte results in an efficient increase of the photovoltaic performance of dye-sensitized solar cells (DSCs).The most effective additives are 4-tert-butylpyridine (TBP), N-methylbenzimidazole (NMBI) and guanidinium thiocyanate (GuNCS) that are adsorbed onto the photoelectrode/electrolyte interface, thus shifting the semiconductor's conduction band edge and preventing recombination with triiodides.Further addition of GuNCS in the optimized electrolytic media causes significant synergistic effects, the action of GuNCS being strongly influenced by the nature of the corresponding co-additive.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Physical Chemistry, NCSR "Demokritos", Aghia Paraskevi Attikis, Athens 15310, Greece. stergt@chem.demokritos.gr.

ABSTRACT
The presence of specific chemical additives in the redox electrolyte results in an efficient increase of the photovoltaic performance of dye-sensitized solar cells (DSCs). The most effective additives are 4-tert-butylpyridine (TBP), N-methylbenzimidazole (NMBI) and guanidinium thiocyanate (GuNCS) that are adsorbed onto the photoelectrode/electrolyte interface, thus shifting the semiconductor's conduction band edge and preventing recombination with triiodides. In a comparative work, we investigated in detail the action of TBP and NMBI additives in ionic liquid-based redox electrolytes with varying iodine concentrations, in order to extract the optimum additive/I2 ratio for each system. Different optimum additive/I2 ratios were determined for TBP and NMBI, despite the fact that both generally work in a similar way. Further addition of GuNCS in the optimized electrolytic media causes significant synergistic effects, the action of GuNCS being strongly influenced by the nature of the corresponding co-additive. Under the best operation conditions, power conversion efficiencies as high as 8% were obtained.

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Variation of the DSCs characteristic parameters as a function of the iodine concentration in the electrolyte. (a) open-circuit potential (Voc), (b) short-circuit photocurrent (Jsc), (c) fill factor (ff), and (d) overall power conversion efficiency (η). Squares correspond to the absence of additive, whereas triangles and circles to the TBP and NMBI addition, respectively.
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Figure 1: Variation of the DSCs characteristic parameters as a function of the iodine concentration in the electrolyte. (a) open-circuit potential (Voc), (b) short-circuit photocurrent (Jsc), (c) fill factor (ff), and (d) overall power conversion efficiency (η). Squares correspond to the absence of additive, whereas triangles and circles to the TBP and NMBI addition, respectively.

Mentions: After incorporation of the electrolytes inside the cells, DSCs were assembled and their J-V characteristics were determined. In a first attempt, the effect of the iodine concentration in the electrolyte (without any additive) was investigated. Table S1 in Additional file 1 presents the photovoltaic parameters obtained from the J-V characteristic curves (Figure S1 in Additional file 1) of the PMII-I2-PC electrolytes, while Figure 1 presents analytically the dependence of the cell parameters (Voc, ff, Jsc and η) on the iodine concentration. As we can see from Figure 1b, the short-circuit photocurrent density (Jsc) decreases systematically as the [I2] increases, in agreement with literature results [19]. The above behaviour can be understood by assuming that whereas a specific critical level of I3- is necessary for cell functioning, further increase of [I2] (or of the produced [I3-]), increases recombination at short-circuit conditions, thus reducing Jsc[20].


Influence of electrolyte co-additives on the performance of dye-sensitized solar cells.

Stergiopoulos T, Rozi E, Karagianni CS, Falaras P - Nanoscale Res Lett (2011)

Variation of the DSCs characteristic parameters as a function of the iodine concentration in the electrolyte. (a) open-circuit potential (Voc), (b) short-circuit photocurrent (Jsc), (c) fill factor (ff), and (d) overall power conversion efficiency (η). Squares correspond to the absence of additive, whereas triangles and circles to the TBP and NMBI addition, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211393&req=5

Figure 1: Variation of the DSCs characteristic parameters as a function of the iodine concentration in the electrolyte. (a) open-circuit potential (Voc), (b) short-circuit photocurrent (Jsc), (c) fill factor (ff), and (d) overall power conversion efficiency (η). Squares correspond to the absence of additive, whereas triangles and circles to the TBP and NMBI addition, respectively.
Mentions: After incorporation of the electrolytes inside the cells, DSCs were assembled and their J-V characteristics were determined. In a first attempt, the effect of the iodine concentration in the electrolyte (without any additive) was investigated. Table S1 in Additional file 1 presents the photovoltaic parameters obtained from the J-V characteristic curves (Figure S1 in Additional file 1) of the PMII-I2-PC electrolytes, while Figure 1 presents analytically the dependence of the cell parameters (Voc, ff, Jsc and η) on the iodine concentration. As we can see from Figure 1b, the short-circuit photocurrent density (Jsc) decreases systematically as the [I2] increases, in agreement with literature results [19]. The above behaviour can be understood by assuming that whereas a specific critical level of I3- is necessary for cell functioning, further increase of [I2] (or of the produced [I3-]), increases recombination at short-circuit conditions, thus reducing Jsc[20].

Bottom Line: The presence of specific chemical additives in the redox electrolyte results in an efficient increase of the photovoltaic performance of dye-sensitized solar cells (DSCs).The most effective additives are 4-tert-butylpyridine (TBP), N-methylbenzimidazole (NMBI) and guanidinium thiocyanate (GuNCS) that are adsorbed onto the photoelectrode/electrolyte interface, thus shifting the semiconductor's conduction band edge and preventing recombination with triiodides.Further addition of GuNCS in the optimized electrolytic media causes significant synergistic effects, the action of GuNCS being strongly influenced by the nature of the corresponding co-additive.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Physical Chemistry, NCSR "Demokritos", Aghia Paraskevi Attikis, Athens 15310, Greece. stergt@chem.demokritos.gr.

ABSTRACT
The presence of specific chemical additives in the redox electrolyte results in an efficient increase of the photovoltaic performance of dye-sensitized solar cells (DSCs). The most effective additives are 4-tert-butylpyridine (TBP), N-methylbenzimidazole (NMBI) and guanidinium thiocyanate (GuNCS) that are adsorbed onto the photoelectrode/electrolyte interface, thus shifting the semiconductor's conduction band edge and preventing recombination with triiodides. In a comparative work, we investigated in detail the action of TBP and NMBI additives in ionic liquid-based redox electrolytes with varying iodine concentrations, in order to extract the optimum additive/I2 ratio for each system. Different optimum additive/I2 ratios were determined for TBP and NMBI, despite the fact that both generally work in a similar way. Further addition of GuNCS in the optimized electrolytic media causes significant synergistic effects, the action of GuNCS being strongly influenced by the nature of the corresponding co-additive. Under the best operation conditions, power conversion efficiencies as high as 8% were obtained.

No MeSH data available.


Related in: MedlinePlus