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Energy Harvesting

We are actively working in position sensitive photodetectors based on organic semiconductors. This research line aims at developing organic photodetectors based on molecular multilayers, which deliver a linear change in photocurrent depending on the position of the impinging light on the pixel. We exploit optical interference in multilayer structures as well as antibatic photocurrent response to produce spatial tuning of photocurrent in one single pixel. [1][2][3] This idea is protected by a patent cooperation treaty (PCT) owned by IMDEA.[4] Based on this concept we have developed devices able to monitor lateral displacements in 1D [1,2] and 2D [5] with a spatial sensitivity in some of them close to 500 m [1].

Figure 1. (a) Vertical section of an organic position photodetector composed of two complementary donor-acceptor wedge layers. (b) Spectral response of the photodetector as a function of the position of the light spot along the pixel. Inset: Front view of the device. (c) Model of the penetration of the light across the different layers as a function of position along the pixel. (d) Calibration curve given by the linear variation of the photocurrent ratio at two wavelengths as a function of displacement.

[1] J. Cabanillas-Gonzalez et al., Appl. Phys. Lett. 99, 103305 (2011).
[2] J. Cabanillas-Gonzalez et al., J. Nanosci. Nanotechnol. 13, 1–6, (2013).
[3] M. Campoy-Quiles et al., Org. Photonics Photovolt.1, 11-23 (2013).
[4] J. Cabanillas-Gonzalez and M. Campoy-Quiles, PCT/ES2011/070841.
[5] X. Rodriguez-Martinez et al., submitted.

  • Dr. Juan Cabanillas González

    PhD: Imperial College London, UK
    Previous Position: Politecnico di Milano, Italy
    Research: Pump probe and photoinduced absoption spectroscopies
    Researcher ID: M-1026-2014
    Joining Date: October, 2009
    User Name: juan.cabanillas
    Telephone: +34 91 299 87 84
    Cabanillas González

    Juan Cabanillas–Gonzalez graduated in Physics at Universidade de Santiago de Compostela in 1999. He got a PhD in Physics from Imperial College London working with photophysics of conjugated polymers with Prof. Donal Bradley. In 2003 he started a post-doctoral stage at Politecnico di Milano with Prof. Guglielmo Lanzani. In 2009 he was appointed Ramon y Cajal fellow at IMDEA Nanociencia (Madrid). His main research interests concern with excited state dynamics in conjugated polymers and the application of these materials to different fields such as lighting, light detection and chemical sensing.

    Research Lines

    The group investigates the use of time-resolved spectroscopy (transient absorption and time-resolved photoluminescence) for the understanding and optimization of fundamental processes in organic-based devices. Additionally we fabricate and characterize devices such as polymer laser resonators, polymer waveguides or photodectors. Currently, our research is focused on these topics:

    1. Photophysics of novel conjugated polymers with improved emission and light amplification properties. Interchain interactions in solid state often lead to unwanted broad photoinduced absorption which overlaps spectrally with stimulated emission. We study the excited-state dynamics of polymers with chemical structures which promote optical gain upon reducing inter-chain interactions. Examples of these poly- mers are conjugated polyrotaxanes with cyclodextrin rings surrounding the backbone, polymers with bulky side-chain substituents or polymers with backbone encapsulated by cyclic side-chain substituents.

    Relevant publications

    • “Role of Amorphous and Aggregate Phases on Field-Induced Exciton Dissociation in a Conjugated Polymer”, Marta M. Mróz et col. Phys. Review B 87, 035201 (11pp) (2013)
    • “Pump-Probe Spectroscopy in Organic Semiconductors: Monitoring Fundamental Processes of Relevance in Optoelectronics” J. Cabanillas- Gonzalez et col. Adv. Mat. 2011, 23, 5468-5485
    • “Photoinduced Transient Stark Spectroscopy in Organic Semiconductors: a Method for Charge Mobility Determination in the Picosecond Regime”, J. Cabanillas-Gonzalez et col. Phys. Rev. Lett. 96,  106601 (4pp) (2006)