Abstract
The conventional charge transport models based on density- and field-dependent mobility, only having a non-Arrhenius temperature dependence, cannot give good current-voltage characteristics of poly (2-methoxy-5-(2′-ethylhexyloxy)-p-phenylene vinylene) (MEH-PPV) hole-only devices. In this paper, we demonstrate that the current-voltage characteristics can give a good unified description of the temperature, carrier density and electric field dependence of mobility based on both the Arrhenius temperature dependence and the non-Arrhenius temperature dependence. Furthermore, we perform a systematic study of charge transport and electrical properties for MEH-PPV. It is shown that the boundary carrier density has an important effect on the current-voltage characteristics. Too large or too small values of boundary carrier density will lead to incorrect current-voltage characteristics. The numerically calculated carrier density is a decreasing function of the distance to the interface, and the numerically calculated electric field is an increasing function of the distance. Both the maximum of carrier density and the minimum of electric field appear near the interface.
Similar content being viewed by others
References
Burroughes J H, Bradley D D C, Brown A R, et al. Light-emitting diodes based on conjugated polymers. Nature, 1990, 347: 539–541
Blom P W M, de Jong M J M, Vleggaar J J M. Electron and hole transport in poly (p-phenylene vinylene) devices. Appl Phys Lett, 1996, 68: 3308–3310
Blom P W M, de Jong M J M, Breedijk S. Temperature dependent electron-hole recombination in polymer light-emitting diodes. Appl Phys Lett, 1997, 71: 930–932
Pautmeier L, Richert R, Bässler H. Poole-Frenkel behavior of charge transport in organic solids with off-diagonal disorder studied by Monte Carlo simulation. Synth Metals, 1990, 37: 271–281
Bässler H. Charge transport in disordered organic photoconductors. Phys Status Solidi B, 1993, 175: 15–57
Gartstein Y N, Conwell E M. High-field hopping mobility in molecular systems with spatially correlated energetic disorder. Chem Phys Lett, 1995, 245: 351–358
Tanase C, Meijer E J, Blom P W M, et al. Unification of the hole transport in polymeric field-effect transistors and light-emitting diodes. Phys Rev Lett, 2003, 91: 216601
Tanase C, Blom P W M, de Leeuw D M. Origin of the enhanced space-charge-limited current in poly (p-phenylene vinylene). Phys Rev B, 2004, 70: 193202
Yu Z G, Smith D L, Saxena A, et al. Molecular geometry fluctuation model for the mobility of conjugated polymers. Phys Rev Lett, 2000, 84: 721–724
Yu Z G, Smith D L, Saxena A, et al. Molecular geometry fluctuations and field-dependent mobility in conjugated polymers. Phys Rev B, 2001, 63: 085202
Pasveer W F, Cottaar J, Tanase C, et al. Unified description of charge-carrier mobilities in disordered semiconducting polymers. Phys Rev Lett, 2005, 94: 206601
Wang L G, Zhang H W, Tang X L, et al. Unified description of charge-carrier mobilities in disordered organic semiconductors based on both Arrhenius and non-Arrhenius temperature dependence. Eur Phys J B, 2010, 74: 1–7
Zhang Y, Blom P W M. Field-assisted ionization of molecular doping in conjugated polymers. Org Electron, 2010, 11: 1261–1267
Markov D E, Tanase C, Blom P W M, et al. Simultaneous enhancement of charge transport and exciton diffusion in poly (p-phenylenev-inylene) derivatives. Phys Rev B, 2005, 72: 045217
Demeyu L, Stafström S, Bekele M. Monte Carlo simulations of charge carrier mobility in semiconducting polymer field-effect transistors. Phys Rev B, 2007, 76: 155202
Kiguchi M, Nakayama M, Shimada T, et al. Electric-field-induced charge injection or exhaustion in organic thin film transistor. Phys Rev B, 2005, 71: 035332
Tanase C, Meijer E J, Blom P W M, et al. Local charge carrier mobility in disordered organic field-effect transistors. Org Electron, 2003, 4: 33–37
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Wang, L., Zhang, H., Tang, X. et al. Characterization of the charge transport and electrical properties in solution-processed semiconducting polymers. Sci. China Phys. Mech. Astron. 55, 786–791 (2012). https://doi.org/10.1007/s11433-012-4709-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11433-012-4709-6