Supplementary information

TiO2 surface nanostructuring for improved dye loading and light scattering in double layered screen printed dye sensitized solar cells

Mahsa Jalali1,2, Roozbeh Siavash Moakhar1,2, Ajay Kushwaha2, Gregory Kia Liang Goh2,*, Sayyed Khatiboleslam Sadrnezhaad1 and Nastaran Riahi-Noori3

1 Departments of Materials Science and Engineering, Sharif University of Technology, Azadi Ave, Tehran, Iran- 11155-9466

2 Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 3 Research Link, Singapore- 117602

3 Niroo Research Institute, Chemistry and Materials Division, Non-Metallic Materials Group, Tehran, Iran

*Corresponding Author: Email: , Phone: (+65) 6874 8346

EIS results of NR and CNR single layered cells without the underlying nanoparticles are shown for comparison in Fig. S1 and their corresponding simulated data based on the transmission line model equivalent circuit (Fig. 6b) are listed in Table S1. It is observed that both single layered devices have larger Rs than that of the double layered cells indicating poorer interfacial contact with the FTO glass, as already observed in previous reports [1,2]. Further, Rt and Rct values of single layered cells are higher than that of double layered cells due to larger voids [1].

Fig. S1 Nyquist plots of electrochemical impedance spectroscopy of the DSSCs based on single layered and double layered smooth and crack nanorods.

Table S1. Electron dynamic parameters estimated from the Nyquist impedance plots for NR and CNR single layered cells

Parameter / NR / CNR
Rs (Ω) / 22.07 / 19.55
RPt (Ω) / 2.26 / 2.13
Rt (Ω) / 13.82 / 11.83
Rct (Ω) / 31.65 / 23.71
Cm (mF) / 0.46 / 0.60
τe (ms) / 14.56 / 14.23
τt (ms) / 6.36 / 7.10
D (×10-4 cm2s-1) / 2.6 / 2.4
hcoll (%) / 56.32 / 56.11
Ln (mm) / 19.67 / 18.40
O (Mho) / 0.17 / 0.34
χ² / 0.00008 / 0.0002

References

[1] Y.P. Lin, S.Y. Lin, Y.C. Lee, Y.W. Chen-Yang, High surface area electrospun prickle-like hierarchical anatase TiO2 nanofibers for dye-sensitized solar cell photoanodes, J. Mater. Chem. A. 1 (2013) 9875.

[2] H. Gao, C. Bao, T. Yu, Y. Yao, F. Li, Y. Yuan, et al., One-dimensional assembly of TiO2 nanoparticles toward enhancing light harvesting and electron transport for application in dye-sensitized solar cells, RSC Adv. 4 (2014) 10519.

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