Improvement of electrical and photovoltaic properties of methyl red dye based photoelectrochemical cells in presence of single walled carbon nanotubes

Abstract

In this work, we investigated the effect of single walled carbon nanotubes (SWCNT) on the electrical and photovoltaic properties of methyl red (MR) dye based photoelectrochemical cell (PEC). MR dye based PEC with LiClO₄ as ion salt were fabricated with and without mixing SWCNT. The cells were characterized through electrical and optical measurements. The performance of the devices changed drastically in presence of SWCNT. The transition voltage and trap energy of the cells were estimated from the steady-state dark current voltage (I-V) analysis. The transition voltage and trap energy decreased for MR dye cell in presence of SWCNT. Open circuit voltage (V_oc), short circuit current (J_sc), fill factor (FF) and power conversion efficiency (η) increased due to the addition of SWCNT. Further measurement of the transient photocurrent showed that the growth and decay of photocurrent was quite faster in presence of SWCNT. The photocurrent decay with time was fitted for both the cells and found to follow a power law relation which indicates dispersive transport mechanism with exponential trap states distributed in between lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) levels. Possible interpretation is done on the lowering of trap energy with the photocurrent. These results suggest that SWCNT lowers the trap energy of the cells by providing efficient percolation pathways for the conduction of charges. It is expected that due to lowering of trap energy the residing time of the free carriers within the traps decreases. In other words, it may also be said that the charge recombination decreases. These factors affect the overall conduction of charges and improve the electrical and photovoltaic properties.

Keywords

methyl red (MR) / single walled carbon nanotubes (SWCNT) / photoelectrochemical cell (PEC) / trap energy / percolation pathways

References

[1] Grätzel M. Photoelectrochemical cells. Nature, 2001, 414(6861): 338–344

[2] Hagberg D P, Marinado T, Karlsson K M, Nonomura K, Qin P, Boschloo G, Brinck T, Hagfeldt A, Sun L. Tuning the HOMO and LUMO energy levels of organic chromophores for dye sensitized solar cells. Journal of Organic Chemistry, 2007, 72(25): 9550–9556

[3] Haldar A, Maity S, Manik N B. Electrical and photovoltaic characterisations of methyl red dye doped solid-state photoelectrochemical cell. Ionics, 2009, 15(1): 79–83

[4] Burke D J, Lipomi D J. Green chemistry for organic solar cells. Energy & Environmental Science, 2013, 6(7): 2053–2066

[5] Hardin B E, Snaith H J, McGehee M D. The renaissance of dye-sensitized solar cells. Nature Photonics, 2012, 6(3): 162–169

[6] Li G, Zhu R, Yang Y. Polymer solar cells. Nature Photonics, 2012, 6(3): 153–161

[7] Islam M R, Maity S, Haldar A, Manik N B, Basu A N. Photocurrent growth and decay behaviour of crystal violet dye-based photoelectrochemical cell in photovoltaic mode. Ionics, 2012, 18(1–2): 209–214

[8] Singh P K, Jadhav N A, Mishra S K, Singh U P, Bhattacharya B. Application of ionic liquid doped solid polymer electrolyte. Ionics, 2010, 16(7): 645–648

[9] Fredin K, Nissfolk J, Boschloo G, Hagfeldt A. The influence of cations on charge accumulation in dye sensitized solar cells. Journal of Electroanalytical Chemistry, 2007, 609(2): 55–60

[10] Shuttle C G, Treat N D, Douglas J D, Fréchet J M J, Chabinyc M L. Deep energetic trap states in organic photovoltaic devices. Advanced Energy Materials, 2012, 2(1): 111–119

[11] Walker A B, Peter L M, Martínez D, Lobato K. Transient photocurrents in dye-sensitized nanocrystalline solar cells. CHIMIA International Journal for Chemistry, 2007, 61(12): 792–795

[12] Li C, Duan L, Li H, Qiu Y. Universal trap effect in carrier transport of disordered organic semiconductors: transition from shallow trapping to deep trapping. Journal of Physical Chemistry C, 2014, 118(20): 10651–10660

[13] Montero J M, Bisquert J. Trap origin of field-dependent mobility of the carrier transport in organic layers. Solid-State Electronics, 2011, 55(1): 1–4

[14] Carr J A, Chaudhary S. On the identification of deeper defect levels in organic photovoltaic devices. Journal of Applied Physics, 2013, 114(6): 064509

[15] Mandoc M M, Kooistra F B, Hummelen J C, de Boer B, Blom P W M. Effect of traps on the performance of bulk heterojunction organic solar cells. Applied Physics Letters, 2007, 91(26): 263505

[16] Dey S K, Islam M R, Manik N B, Basu A N. Study on the effect of trap levels on steady-state dark I-V characteristics in Safranine-T-based solid-state thin film photoelectrochemical cell. Journal of Materials Science Materials in Electronics, 2002, 13(5): 249–252

[17] Islam M R, Saha S, Manik N B, Basu A N. Transient current study in Safranine-T dye based organic photo-electrochemical cell using exponentially distributed trap assisted charge transport model. Indian Journal of Physics, 2012, 86(12): 1101–1106

[18] Chen J, Yan Y, Lin K. Effects of carbon nanotubes on dye-sensitized solar cells. Journal of the Chilean Chemical Society, 2010, 57(5B): 1180–1184

[19] Hosni M, Kusumawati Y, Farhat S, Jouini N, Pauporté T. Effects of oxide nanoparticle size and shape on electronic structure, charge transport and recombination in dye-sensitized solar cell photoelectrodes. Journal of Physical Chemistry C, 2014, 118 (30): 16791–16798

[20] Ausman K D, Piner R, Lourie O, Ruoff R S. Organic solvent dispersions of single-walled carbon nanotubes: towards solutions of pristine nanotubes. Journal of Physical Chemistry B, 2000, 104 (38): 8911–8915

[21] Lee K M, Hu C W, Chen H W, Ho K C. Incorporating carbon nanotube in a low-temperature fabrication process for dye-sensitized TiO₂ solar cells. Solar Energy Materials and Solar Cells, 2008, 92(12): 1628–1633

[22] Somani S P, Somani P R, Umeno M. Carbon nanotube incorporation: a new route to improve the performance of organic-inorganic heterojunction solar cells. Diamond and Related Materials, 2008, 17(4–5): 585–588

[23] Chakraborty S, Manik N B. Effect of COOH-functionalized SWCNT addition on the electrical and photovoltaic characteristics of Malachite Green dye based photovoltaic cells. Journal of Semiconductors, 2014, 35 (12): 124004

[24] Maity S, Haldar A, Manik N B. Effect of plasticizer on Safranine-T-dye-based solid-state photo electrochemical cell. Ionics, 2008, 14(6): 549–554

[25] Alam A, Sachar S, Puri N, Saxena R K. Interactions of polydispersed single-walled carbon nanotubes with T cells resulting in downregulation of allogeneic CTL responses in vitro and in vivo. Nanotoxicology, 2013, 7(8): 1351–1360

[26] Haldar A, Maity S, Manik N B. Effect of back electrode on photovoltaic properties of crystal-violet-dye-doped solid-state thin film. Ionics, 2008, 14(5): 427–432

[27] Mahmoud M A, Poncheri A, Badr Y, Abd El Wahed M G. Photocatalytic degradation of methyl red dye: research letter. South African Journal of Science, 2009, 105(7–8): 299–303

[28] Buitrón G, Quezada M, Moreno G. Aerobic degradation of the azo dye acid red 151 in a sequencing batch biofilter. Bioresource Technology, 2004, 92(2): 143–149

[29] Yang J, Shen J. Effects of discrete trap levels on organic light emitting diodes. Journal of Applied Physics, 1999, 85(5): 2699–2705

[30] Shen J, Yang J. Physical mechanisms in double-carrier trap-charge limited transport processes in organic electroluminescent devices: A numerical study. Journal of Applied Physics, 1998, 83(12): 7706–7714

[31] Mark P, Helfrich W. Space-charge-limited currents in organic crystals. Journal of Applied Physics, 1962, 33(1): 205–215

Acknowledgements

The authors thank University Grant Commission (UGC), India and Council of Scientific and Industrial Research (CSIR), India for providing financial support for carrying out the research work.

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2014 Higher Education Press and Springer-Verlag Berlin Heidelberg