Abstract
We present an analytic description for the loss of photocurrent efficiency at moderate light intensities and demonstrate a simple technique for extracting the mobility of electrons in semiconducting polymer layers. The underlying theoretical analysis, which is based on a simple drift-recombination scheme, shows good agreement with the measured intensity dependent photocurrent quantum efficiency. The electron mobility extraction is demonstrated for pristine MEH-PPV. The same physical framework is then used to describe the switch on of the photocurrent and the buildup of electron and hole concentrations inside the device. By analyzing the time evolution of the measured photocurrent transient we find an independent verification for the results extracted from the intensity dependence measurements. We use the combination of theoretical and experimental study to discuss the role recombination and space charge effects in reducing photocurrent efficiency.
Similar content being viewed by others
References
N. Tessler and N. Rappaport, “Excitation density dependence of photocurrent efficiency in low mobility semiconductors,” Journal of Applied Physics, vol. 96, pp. 1083–1087, 2004.
E. M. Horsche, D. Haarer, and H. Scher, “Transition from dispersive to nondispersive transport: Photoconduction of polyvinylcarbazole,” Phys. Rev. B, vol. 35, pp. 1273–1280, 1987.
N. Marc, J. Y. Moisan, N. Wolffer, B. Andre, and R. Lever, “Determination of the charge mobility in organic photoconductors by a new method - Theoretical study and experimental results,” Philosophical Magazine B-Physics of Condensed Matter Statistical Mechanics Electronic Optical and Magnetic Properties, vol. 74, pp. 81–91, 1996.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Rappaport, N., Tessler, N. Power Dependence and Turn-On Dynamics of Polymer Photocells - Extracting Mobilities and Analyzing Morphologies. MRS Online Proceedings Library 871, 510 (2005). https://doi.org/10.1557/PROC-871-I5.10
Published:
DOI: https://doi.org/10.1557/PROC-871-I5.10