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arXiv · 1501.07643

Steady-state photoconductivity and multi-particle interactions in rubrene single crystals

P. Irkhin·H. Najafov·V. Podzorov
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Abstract

We demonstrate that photoconductivity of pristine rubrene crystals exhibits several distinct regimes, in which photocurrent as a function of cw (continuous wave) excitation intensity is described by a power law with exponents sequentially taking values 1, 1/3 and 1/4. We show that this photocurrent is generated almost exclusively at the surface of pristine rubrene crystals, while the bulk photocurrent is dramatically smaller and follows a different set of exponents, 1 and 1/2. A model based on exciton fission, fusion and triplet-charge quenching is developed to describe these non-trivial effects in photoconductivity of highly ordered organic semiconductors.

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P. Irkhin, H. Najafov, V. Podzorov. 2015-01-30. Steady-state photoconductivity and multi-particle interactions in rubrene single crystals. https://doi.org/10.1038/srep15323

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