The Influence of Doping of Fullerene Derivative (PCBM) on the Optical Properties of Vanadyl Phthalocyanine (VOPc)

This paper presents a spectroscopic study on doping of Vanadyl pathalocyanine (VOPc) by [6,6]-phenyl C61 butyric acid methyl ester (PCBM). The films are characterized by UV/Vis/NIR spectroscopy. A drastic increase in the absorption coefficient has been observed with increasing dopant concentration. Optical properties of VOPc:PCBM films deposited by spin coating technique were studied in detail. Optical band gap decreased with the PCBM incorporation in the VOPc film. Optical band gap calculated from the absorption spectra decreased from 3.32 eV to 3.26 eV with a variation of 0–75 % of PCBM concentration in the VOPC films.




References:
[1] S. E. Shaheen, et al., "2.5% efficient organic plastic solar cells,"
Applied Physics Letters, vol. 78, p. 841, 2001.
[2] M. Reyes-Reyes, et al., "High-efficiency photovoltaic devices based on
annealed poly (3-hexylthiophene) and 1-(3-methoxycarbonyl)-propyl-1-
phenyl-(6, 6) C blends," Applied Physics Letters, vol. 87, p. 083506,
2005.
[3] Y. X. Liu, et al., "Resonance energy transfer from organic
chromophores to fullerene molecules," Journal of Applied Physics, vol.
99, p. 093521, 2006.
[4] T. J. Savenije, et al., "Mobility and decay kinetics of charge carriers in
photoexcited PCBM/PPV blends," Physical Review B, vol. 69, p.
155205, 2004.
[5] S. Cook, et al., "Singlet exciton transfer and fullerene triplet formation
in polymer-fullerene blend films," Applied Physics Letters, vol. 89, p.
101128, 2006.
[6] R. K. Singh, et al., "Poly(3-hexylthiophene): Functionalized singlewalled
carbon nanotubes: (6,6)-phenyl-C61-butyric acid methyl ester
composites for photovoltaic cell at ambient condition," Solar Energy
Materials and Solar Cells, vol. 94, pp. 2386-2394, 2010.
[7] S. V. Bhat and F. L. Deepak, "Tuning the bandgap of ZnO by
substitution with Mn2+, Co2+ and Ni2+," Solid State Communications,
vol. 135, pp. 345-347, 2005.
[8] C. Yang and S. Holdcroft, "Thermochromism and Band-Gap Tuning of
Acrylated Poly(3-alkylthiophenes)," Synthetic Metals, vol. 84, pp. 563-
564, 1997.
[9] M. B. Ortu├▒o-L├│pez, et al., "Optical band gap tuning and study of
strain in CdS thin films," Vacuum, vol. 76, pp. 181-184, 2004.
[10] F. F. MUHAMMAD and K. SULAIMAN, "Tuning the Optical Band
Gap of DH6T by Alq3 Dopant," Sains Malaysiana, vol. 40, pp. 17-20,
2011.
[11] C. C. Leznoff and A. B. P. Lever, Phthalocyanines: Properties and
Applications VCH, New York 1996.
[12] I. Rosenthal, "Phthalocyanines as photodynamic sensitizers,"
Photochemistry and photobiology, vol. 53, p. 859, 1991.
[13] R. M. Christie and B. G. Freer, "Colour and constitution relationships
in organic pigments:: Part 3--phthalocyanines," Dyes and Pigments, vol.
24, pp. 113-124, 1994.
[14] K. Krishnakumar and C. Menon, "Electrical and Optical
Characterization of Vacuum Evaporated Magnesium Phthalocyanine
Thin Films* 1," Journal of Solid State Chemistry, vol. 128, pp. 27-29,
1997.
[15] S. Singh, et al., "Optical and infrared spectroscopic studies of chemical
sensing by copper phthalocyanine thin films," Materials Chemistry and
Physics, vol. 112, pp. 793-797, 2008.
[16] M. El-Nahass and S. Yaghmour, "Effect of annealing temperature on
the optical properties of thermally evaporated tin phthalocyanine thin
films," Applied Surface Science, vol. 255, pp. 1631-1636, 2008.
[17] Q. Chen, et al., "Local electrical properties of vanadyl phthalocyanine
multilayers studied by atomic force microscopy," Molecular Crystals
and Liquid Crystals, vol. 337, pp. 505-509, 1999.
[18] S. M. Khan, et al., "Investigation of temperature-dependent electrical
properties of p-VOPc/n-si heterojunction under dark conditions," Ionics,
pp. 1-7.
[19] H. Wang, et al., "High mobility vanadyl-phthalocyanine polycrystalline
films for organic field-effect transistors," Applied Physics Letters, vol.
90, p. 253510, 2007.
[20] A. T. Davidson, "The effect of the metal atom on the absorption spectra
of phthalocyanine films," The Journal of Chemical Physics, vol. 77, p.
168, 1982.
[21] S. Senthilarasu, et al., "Thermally evaporated ZnPc thin films--band gap
dependence on thickness," Solar Energy Materials and Solar Cells, vol.
82, pp. 179-186, 2004.
[22] G. Ruani, et al., "Photoinduced charge transfer in complex architectured
films of c60 and donor-like molecules," Synthetic Metals, vol. 103, pp.
2392-2394, 1999.
[23] J. Bardeen, et al., in Photoconductivity Conference, New York, Wiley,
1965.
[24] S. Ambily and C. S. Menon, "Electrical conductivity studies and optical
absorption studies in copper phthalocyanine thin films," Solid State
Communications, vol. 94, pp. 485-487, 1995.
[25] R. A. Collins, et al., "Optical properties of lead phthalocyanine (PbPc)
thin films," Thin solid films, vol. 229, pp. 113-118, 1993.
[26] A. Krier, et al., "The influence of chlorine on the optical properties of
monoclinic lead phthalocyanine thin films," Advanced Materials for
Optics and Electronics, vol. 2, pp. 289-293, 1993.
[27] M. El-Nahass, et al., "Optical properties of evaporated FePc thin films,"
Journal of Optics vol. 30, p. 121, 2001.
[28] J. Robertson, Philosophical Magazine Letters vol. 57, p. 143, 1988.