Scientific Publications

Small

by Sergi Riera-Galindo; Marta Sanz-Lleó; Edgar Gutiérrez-Fernández; Nicolás Ramos; Marta Mas-Torrent; Jaime Martín; Laura López-Mir; and Mariano Campoy-Quiles

ABSTRACT

Simple synthetic routes, high active layer thickness tolerance as well as stable organic solar cells are relentlessly pursued as key enabling traits for the upscaling of organic photovoltaics. Here, the potential to address these issues by tuning donor polymer molecular weight is investigated. Specifically, the focus is on PTQ10, a polymer with low synthetic complexity, with number average molecular weights of 2.4, 6.2, 16.8, 52.9, and 54.4 kDa, in combination with three different non-fullerene acceptors, namely Y6, Y12, and IDIC. Molecular weight, indeed, unlocks a threefold increase in power conversion efficiency for these blends. Importantly, efficiencies above 10% for blade coated devices with thicknesses between 200 and 350 nm for blends incorporating high molecular weight donor are shown. Spectroscopic, GIWAXS and charge carrier mobility data suggest that the strong photocurrent improvement with molecular weight is related to both, improved electronic transport and polymer contribution to exciton generation. Moreover, it is demonstrated that solar cells based on high molecular weight PTQ10 are more thermally stable due to a higher glass transition temperature, thus also improving device stability.

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Advanced Science

by Ignasi Burgués-Ceballos; Paula Pinyol-Castillo; Aina López-Porta; Enric Pascual; Tomáš Syrový; Lucie Syrova; Frantisek Josefik; Benjamin Dhuiège; Irene Serrano; Paul D. Lacharmoise; Laura López-Mir

ABSTRACT

While organic photovoltaics are accessing specific application sectors taking advantage of their unique properties, it is important to identify as many differentiators as possible to expand the market penetration and consolidation of this technology. In this work, for the first time, the large-scale fabrication of organic photovoltaic modules embedded into structural plastic parts through industrial injection molding is demonstrated. Thermoplastic polyurethane is chosen as the injected material to show that this additional processing step can yield flexible, lightweight photovoltaic modules with enhanced device robustness and virtually unchanged performance. The critical optomechanical and physico-chemical material properties, as well as the plastic processing parameters to enable in-mold plastic solar cells with improved performance and stability, are discussed and provided with perspective.

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Doctoral Thesis

by Pinyol, Paula

ABSTRACT

The main objective of the project was to manufacture organic photovoltaic devices (OPV) and incorporate them into injected plastic parts, without losing their functionality. Firstly, the different layers that make up the OPVs have been optimised. Secondly, devices have been manufactured on rigid and flexible substrates using printing techniques (Dr. Blade, Slot-Die and screen printing) and thermal evaporation. Thirdly, the use of thermoplastic polyurethane (TPU) and polycarbonate (PC) for the injection of OPV devices has been compared using a thermoplastic polymer injection molding; the samples have been previously prepared with backing film, barrier film and different types of adhesives.

Thanks to the characterisation of the samples by J-V curves, 4-point, EQE, absorbance and LBIC measurements, the effect of the different manufacturing and injection process parameters of the devices has been monitored. Regarding the configuration of the devices, it has been determined that the PM6 donor material has a higher absorbance than PTQ10, although PTQ10 is able to generate a higher potential difference. In addition, the addition of IDIC to the tested systems improves the charge extraction. A system has also been established to optimise the thickness of the photoactive layer (PAL) according to the OPV materials. In this line, it is concluded that semi-transparent OPVs need higher PAL thickness to achieve photocurrents approaching those obtained with evaporated layers. As for printed electrodes, inks based on silver nanowires (AgNWs) or PEDOT:PSS have been identified as having great potential to replace ITO as the bottom electrode, due to their low resistivity and high transmittance; however, issues related to stack compatibility, roughness and layer stability remain to be solved. Finally, OPV devices fabricated with ITO and Flextrode (commercial Ag and PEDOT:PSS electrode) have shown a satisfactory tolerance to the injection process, maintaining an average of ~90% of their original efficiency. It is concluded that OPV devices with PM6 as active layer donor material and TPU as injected thermoplastic material achieve higher functionality. On the other hand, samples injected with PC show a drastic decrease in their functionality, presumably due to the degradation of the active layer at higher injection temperatures.

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iarigai/IC Conference 2022

by Syrový, Tomáš; Josefík, František; Syrová, Lucie; Burgués, Ignasi; Janíček, Petr; Rodriguez, Jhonatan; Kubáč, Lubomír; López, Laura

ABSTRACT

The study focuses on the optimization of PEDOT:PSS ink for the preparation of a hole transport layer. The ink was developed for the spiral bar coating technique and for subsequent organic photodetector preparation. In this study, the effect of various variables such as secondary dopant, surfactant, PEDOT:PSS complex ratio, and ink composition on selected characteristics such as conductivity, work function, charge carrier mobility, etc. is demonstrated.

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IEEE International Symposium on Antennas and Propagation

by Sidibe, Alassane; Lopez-Mir, Laura; Dhuiège, Benjamin; Depres, Gaël; Takacs, Alexandru; Mennekens, Jan

ABSTRACT

This paper presents the design and characterisation of an antenna on a paper-based substrate. The antenna is designed on a nanocellulose foil optimised with a highly conductive ink based on silver nanoparticles. The electrical and dielectric properties of the materials were characterised prior to the antenna simulation. The antenna is designed to operate at the ISM 868 MHz frequency band and has a maximum gain of +1.7 dBi. Its development is part of the first step in the implementation of a flexible battery-free geolocation tag, remotely powered by UHF Energy sources in the European RFID spectrum between 865.6 MHz and 867.6 MHz. An accurate characterisation procedure was carried out and the results show good agreement with the simulations.

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International Conference on Flexible Printable Sensors and Systems

by López Mir, L.; Sidibe, A.; López-Porta, A.; Pascual, E.; Dhuiège, B.; Depres, G.

ABSTRACT

This paper presents a preliminary study for the construction of an in-mould smart tag as a robust flexible label with a radiofrequency wireless power transmission system and enhanced geolocation features. The proposed flexible geolocation tag is realised by means of a specific production process applied over printed antennas and hybridized rigid control module. Advanced materials such as highly conductive inks and nanocellulose-based substrates, as well as innovative manufacturing processes covered by the in-mould electronics framework, are investigated. The effect of the thermoplastic used for in-mould process on the antenna is explored by simulations and experimental validation.

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OPE Journal

New transparent conductive inks and hole transport layer inks for transparent electrodes and photovoltaics applications

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