Improved efficiency of dye-sensitized solar cells by design of a proper double layer photoanode electrodes composed of Cr-doped TiO2 transparent and light scattering layers

  • M. R. Mohammadi
  • A. M. Bakhshayesh
  • F. Sadri
  • M. Masroor
Original Paper


A new strategy for enhancing the efficiency of TiO2 dye-sensitized solar cells (DSSCs) by design of a new double layer film doped with Cr ions, with various morphologies, is reported. X-ray diffraction and field emission scanning electron microscope (FE-SEM) analyses revealed that the synthesized nanoparticles had uniform and nanometer grains with different phase compositions and average crystallite size in the range of 10–12 nm depending upon Cr atomic percentage. UV–vis absorption showed that Cr introduction enhanced the visible light absorption of TiO2 nanoparticles by shifting the absorption onset to visible light region. Furthermore, the band gap energy of nanoparticles decreased with an increase in dopant concentration due to reduction of particle size. It was found that, 3 at.% Cr-doped TiO2 DSSC in the form of a double-layer film composed of TiO2 nanoparticles, as the under-layer, and mixtures of nano- and micro-particles with weight ratio of 80:20, as the over-layer, (i.e., CT3/NM3 solar cell) had the highest power conversion efficiency of 7.02 %, short current density of 17.32 mA/cm2 and open circuit voltage of 674 mV. This can be related to achievement of a balance among the electron injection, light scattering effect and dye sensitization parameters. Optimization of light scattering effect of photoanode electrode led to improve the photovoltaic performance of CT3/NM3 double-layer solar cell and was demonstrated by diffuse reflectance spectroscopy. The presented strategy would open up new insight into fabrication of low-cost TiO2 DSSCs with high power conversion efficiency.


Cr-doped TiO2 Dye-sensitized solar cell Light scattering effect Double layer film 



The authors would like to thank Iran Nanotechnology Initiative Council for the financial support.


  1. 1.
    O’Regan B, Grätzel M (1991) A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films. Nature 353:737–739CrossRefGoogle Scholar
  2. 2.
    Yella A, Lee HW, Tsao HN, Yi C, Chandiran AK, Nazeeruddin MK, Diau EWG, Yeh CY, Zakeeruddin SM, Gratzel M (2011) Prophyrin-sensitized solar cells with cobalt (II-III)-based redox electrolyte exceeds 12 percent efficiency. Science 334:629–634CrossRefGoogle Scholar
  3. 3.
    Hagfeldt A, Grätzel M (2000) Molecular photovoltaics. Acc Chem Res 33:269–277CrossRefGoogle Scholar
  4. 4.
    Fujishima A, Zhang X, Tryk DA (2008) TiO2 photocatalysis and related surface phenomena. Surf Sci Rep 63:515–582CrossRefGoogle Scholar
  5. 5.
    Su R, Bechstein R, Kibsgaard J, Vang RT, Besenbacher F (2012) High-quality Fe-doped TiO2 films with superior visible-light performance. J Mater Chem 22:23755–23758CrossRefGoogle Scholar
  6. 6.
    Kim DH, Lee KS, Kim YS, Chung YC, Kim SJ (2006) Photocatalytic activity of Ni 8 wt%-doped TiO2 photocatalyst synthesized by mechanical alloying under visible light. J Am Ceram Soc 89:515–518CrossRefGoogle Scholar
  7. 7.
    Karunakaran C, Abiramasundari G, Gomathisankar P, Manikandan G, Anandi V (2010) Cu-doped TiO2 nanoparticles for photocatalytic disinfection of bacteria under visible light. J Colloid Interface Sci 352:68–74CrossRefGoogle Scholar
  8. 8.
    Deng GR, Xia XH, Guo ML, Gao Y, Shao G (2011) Mn-doped TiO2 nanopowders with remarkable visible light photocatalytic activity. Mater Lett 65:2051–2054CrossRefGoogle Scholar
  9. 9.
    Matsumoto Y, Murakami M, Shono T, Hasegawa T, Fukumura T, Kawasaki M, Ahmet P, Chikyow T, Koshihara SY, Koinuma H (2001) Room-temperature ferromagnetism in transparent transition metal-doped titanium dioxide. Science 291:854–856CrossRefGoogle Scholar
  10. 10.
    Lü X, Mou X, Wu J, Zhang D, Zhang L, Huang F, Xu F, Huang S (2010) Improved-performance dye-sensitized solar cells using Nb-doped TiO2 electrodes: efficient electron injection and transfer. Adv Funct Mater 20:509–515CrossRefGoogle Scholar
  11. 11.
    Choudhury B, Choudhury A (2012) Dopant induced changes in structural and optical properties of Cr3+ doped TiO2 nanoparticles. Mater Chem Phys 132:1112–1118CrossRefGoogle Scholar
  12. 12.
    Yu JC, Li GS, Wang XC, Hu XL, Leung CW, Zhang ZD (2006) An ordered cubic Im3 m mesoporous Cr–TiO2 visible light photocatalyst. Chem Commun 25:2717–2719CrossRefGoogle Scholar
  13. 13.
    Irie H, Shibanuma T, Kamiya K, Miura S, Yokoyama T, Hashimoto K (2010) Characterization of Cr(III)-grafted TiO2 for photocatalytic reaction under visible light. Appl Catal B Environ 96:142–147CrossRefGoogle Scholar
  14. 14.
    Peng YH, Huang GF, Huang WQ (2012) Visible-light absorption and photocatalytic activity of Cr-doped TiO2 nanocrystal films. Adv Powder Technol 23:8–12CrossRefGoogle Scholar
  15. 15.
    Lyson B, Gwizdz P, Czapla A, Lubecka M, Zakrzewska K, Biernacka K, Radecka M, Michalow-Mauke M, Graule T, Balogh AG, Lauterbach S, Kleebe HG (2011) TiO2:Cr nanopowders for hydrogen sensing. Procedia Eng 25:749–752CrossRefGoogle Scholar
  16. 16.
    Xie Y, Huang N, You S, Liu Y, Sebo B, Liang L, Fang X, Liu W, Guo S, Zhao XZ (2013) Improved performance of dye-sensitized solar cells by trace amount Cr-doped TiO2 photoelectrodes. J Power Sources 224:168–173CrossRefGoogle Scholar
  17. 17.
    Zhang Q, Cao G (2011) Nanostructured photoelectrodes for dye-sensitized solar cells. Nano Today 6:91–109CrossRefGoogle Scholar
  18. 18.
    Johnson RW, Thiele ES, French RH (1997) Light-scattering efficiency of white pigments: an analysis of model core-shell pigments vs. optimized rutile TiO2. Tappi J 80:233–239Google Scholar
  19. 19.
    Ross WD (1971) Theoretical computation of light scattering power: comparison between TiO2 and air bubbles. J Paint Technol 43:50–66Google Scholar
  20. 20.
    Hore S, Vetter C, Kern R, Smit H, Hinsch A (2006) Influence of scattering layers on efficiency of dye-sensitized solar cells. Sol Energ Mater Sol C 90:1176–1188CrossRefGoogle Scholar
  21. 21.
    Xu H, Tao X, Wang DT, Zheng YZ, Chen JF (2010) Enhanced efficiency in dye-sensitized solar cells based on TiO2 nanocrystal/nanotube double-layered films. Electrochim Acta 55:2280–2285CrossRefGoogle Scholar
  22. 22.
    Bakhshayesh AM, Mohammdi MR, Fray DJ (2012) Controlling electron transport rate and recombination process of TiO2 dye-sensitized solar cells by design of double-layer films with different arrangement modes. Electrochim Acta 78:384–391CrossRefGoogle Scholar
  23. 23.
    Kong FT, Dai SY, Wang KJ (2007) Review of recent progress in dye-sensitized solar cells. Adv OptoElectron 2007:1–13Google Scholar
  24. 24.
    Yanagida M, Onozawa-Komatsuzaki N, Kurashige M, Sayama K, Sugihara H (2010) Optimization of tandem-structured dye-sensitized solar cell. Sol Energ Mat Sol C 94:297–302CrossRefGoogle Scholar
  25. 25.
    Kim C, Kim KS, Kim HY, Han YS (2008) Modification of a TiO2 photoanode by using Cr-doped TiO2 with an influence on the photovoltaic efficiency of a dye-sensitized solar cell. J Mater Chem 18:5809–5814CrossRefGoogle Scholar
  26. 26.
    Mohammadi MR, Ghorbani M, Cordero-Cabrera MC, Fray DJ (2006) Synthesis of high surface area nanocrystalline anatase-TiO2 powders derived from particulate sol–gel route by tailoring processing parameters. J Sol-Gel Sci Technol 40:15–23CrossRefGoogle Scholar
  27. 27.
    Shannon RD (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallogr A 32:751–767CrossRefGoogle Scholar
  28. 28.
    Mohammadi MR, Louca RRM, Fray DJ, Welland ME (2012) Dye-sensitized solar cells based on a single layer deposition of TiO2 from a new formulation paste and their photovoltaic performance. Sol Energ 86:2654–2664CrossRefGoogle Scholar
  29. 29.
    Ito S, Liska P, Pechy P, Bach U, Nazeeruddin MK, Kay A, Zekeeruddin SM, Grätzel M (2005) Control of dark current in photoelectrochemical (TiO2/I–I3−) and dye-sensitized solar cells. Chem Commun 34:4351–4353CrossRefGoogle Scholar
  30. 30.
    Koparde VN, Cummings PT (2008) Phase transformations during sintering of titania nanoparticles. ACS Nano 2:1620–1624CrossRefGoogle Scholar
  31. 31.
    Bakardjieva S, Stengl V, Szatmary L, Subrt J, Lukac J, Murafa N, Niznansky D, Cizek K, Jirkovsky J, Petrova N (2006) Transformation of brookite-type TiO2 nanocrystals to rutile: correlation between microstructure and photoactivity. J Mater Chem 16:1709–1716CrossRefGoogle Scholar
  32. 32.
    Yan BF, Chen B, Mahurin SM, Schwartz V, Mullins DR, Lupini AR, Pennycook SJ, Dai S, Overbury SH (2005) Preparation and comparison of supported gold nanocatalysts on anatase, brookite, rutile, and P25 polymorphs of TiO2 for catalytic oxidation of CO. J Phys Chem B 109:10676–10685CrossRefGoogle Scholar
  33. 33.
    Zhang H, Banfdield JF (2000) Understanding polymorphic phase transformation behavior during growth of nanocrystalline aggregates: insights from TiO2. J Phys Chem B 104:3481–3487CrossRefGoogle Scholar
  34. 34.
    Gribb A, Banfield JF (1997) Particle size effects on transformation kinetics and phase stability in nanocrystalline TiO2. Am Mineral 82:717–728Google Scholar
  35. 35.
    Cullity BD (1987) Elements of X-ray diffraction. Addison-Wesley Publishing Company, LondonGoogle Scholar
  36. 36.
    Ruiz AM, Sakai G, Cornet A, Shimanoe K, Morante JR, Yamazoe N (2003) Cr-doped TiO2 gas sensor for exhaust NO2 monitoring. Sens Actuators B Chem 93:509–518CrossRefGoogle Scholar
  37. 37.
    Grätzel M (2005) Solar energy conversion by dye-sensitized photovoltaic cells. Inorg Chem 44:6841–6851CrossRefGoogle Scholar
  38. 38.
    Tauc J (1974) Amorphous and liquid semiconductors. Plenum Press, LondonCrossRefGoogle Scholar
  39. 39.
    Qi L, Liu Y, Li C (2010) Controlled synthesis of TiO2-B nanowires and nanoparticles for dye-sensitized solar cells. Appl Surf Sci 257:1660–1665CrossRefGoogle Scholar
  40. 40.
    Feigenbrugel V, Loew C, Calvé SL, Mirabel P (2005) Near-UV molar absorptivities of acetone, alachlor, metolachlor, diazinon and dichlorvos in aqueous solution. J Photochem Photobiol A Chem 174:76–81CrossRefGoogle Scholar
  41. 41.
    Chen L, Graham ME, Li G, Gray KA (2006) Fabricating highly active mixed phase TiO2 photocatalysts by reactive DC magnetron sputter deposition. Thin Solid Films 515:1176–1181CrossRefGoogle Scholar
  42. 42.
    Li G, Ciston S, Saponjic Z, Chen L, Dimitrijevic N, Rajh T, Gray KA (2008) Synthesizing mixed-phase TiO2 nanocomposites using a hydrothermal method for photo-oxidation and photoreduction applications. J Catal 253:105–110CrossRefGoogle Scholar
  43. 43.
    Li G, Chen L, Graham ME, Gray KA (2007) A comparison of mixed phase titania photocatalysts prepared by physical and chemical methods: the importance of the solid–solid interface. J Mol Catal A Chem 275:30–35CrossRefGoogle Scholar
  44. 44.
    Hurum DC, Agrios AG, Gray KA, Rajh T, Thurnauer MC (2003) Explaining the enhanced photocatalytic activity of Degussa P25 mixed-phase TiO2 using EPR. J Phys Chem B 107:4545–4549CrossRefGoogle Scholar
  45. 45.
    Wang H, Su C, Chen HS, Liu YC, Hsu YW, Hsu NM, Li WR (2011) Preparation of nanoporous TiO2 electrodes for dye-sensitized solar cells. J Nanomater. doi: 10.1155/2011/547103 Google Scholar
  46. 46.
    Kim BM, Rho SG, Kang CH (2011) Effects of TiO2 structures in dye-sensitized solar cell. J Nanosci Nanotechnol 11:1515–1517CrossRefGoogle Scholar
  47. 47.
    Yang L, Lin Y, Jia J, Xiao X, Li X, Zhou X (2008) Light harvesting enhancement for dye-sensitized solar cells by novel anode containing cauliflower-like TiO2 spheres. J Power Sources 182:370–376CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • M. R. Mohammadi
    • 1
  • A. M. Bakhshayesh
    • 1
  • F. Sadri
    • 1
  • M. Masroor
    • 1
  1. 1.Department of Materials Science and EngineeringSharif University of TechnologyTehranIran

Personalised recommendations