Photoactive Molecular Junctions Based on Self-Assembled Monolayers of Indoline Dyes

Caranzi, L and Pace, G and Guarnera, S and Canesi, E V and Brambilla, L and Raavi, Sai Santosh Kumar and Petrozza, A and Caironi, M (2014) Photoactive Molecular Junctions Based on Self-Assembled Monolayers of Indoline Dyes. ACS Applied Materials and Interfaces, 6 (22). pp. 19774-19782. ISSN 1944-8244 (In Press)

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Abstract

We demonstrate the feasibility of a photodetector based on an ensemble molecular junction, where a self-assembled monolayer of an organic donor-acceptor dye is directly sandwiched between two electrodes. In such a device, upon photoexcitation and generation of a charge-transfer state on the molecule, charges are dissociated and directly collected at the electrodes without the need of transport through a bulk phase, as in usual photodetectors. We show that the device can work in photovoltaic regime and the spectral response can be tuned by varying the light absorbing dye. Therefore, the electro-optical properties of the downscaled device can be unambiguously related to the physical-chemical properties of the molecules, a commonly difficult point to demonstrate in a molecular junction device, due to the uncertainties of the interplay between molecules and electrodes. The proposed device, which relies on a simple self-assembly process, has a strong potentiality for fast responding, downscaled detectors, ultimately limited by charge dissociation dynamics and can be considered also as a useful tool to investigate fundamental electro-optical processes in molecular monolayers.

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IITH Creators:

IITH Creators	ORCiD
Raavi, Sai Santosh Kumar	http://orcid.org/0000-0002-2496-9233

Item Type:

Article

Additional Information:

The authors acknowledge the kind support and help o f D. Natali, F. Maddalena, A. Iacchetti, M. Binda, A. Grimoldi and A. R. Srimath Kandada wit h the data interpretation of impedance measurements, EQE measurements and transient absorp tion measurements.

Uncontrolled Keywords:

molecular electronics, self assembled monolayers, molecular junctions, photodetectors, organic dyes

Subjects:

Physics

Divisions:

Department of Physics

Depositing User:

Team Library

Date Deposited:

10 Nov 2014 05:51

Last Modified:

11 Sep 2017 06:59