Ignasi Burgués-Ceballos

We develop spectrally selective organic photovoltaics with a 4.5% light utilisation efficiency for plants and integrate them into open-field, flexible agricultural infrastructures.

Increasing the donor’s molecular weight improves transport and enables high-efficiency solar cells with reduced donor content, which in turn improves transparency, leading to boosted semitransparent photovoltaics.

Recent developments have introduced bimetallic nanoparticles as effective cocatalysts for photocatalytic systems. This review explores the rapidly expanding research on bimetallic cocatalysts for photocatalytic production of hydrogen, emphasizing the creation of carrier‐selective contacts, localized surface plasmon resonance effects, methodologies for their preparation, promising metal combinations as cocatalyst materials and operando studies of bimetallic cocatalysts in order to study how the metallic components of the cocatalyst reorganize in real‐time under light exposure during the photocatalytic reactions and, hence, to establish structure‐property relationships that could explain the observed photocatalytic performance. The goal of this review is to furnish readers with a comprehensive overview of photocatalytic hydrogen production boosted by bimetallic nanoparticles and to inspire further innovative studies on bimetallic cocatalytic materials, which can potentially revolutionize applications in energy and materials science.

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.

We mix small-size and large-size AgBiS₂ nanocrystals in a gradient fashion to judiciously favour the band alignment and maximise charge transport. Thin film solar cells show 7.3% efficiency and visible-near infrared photodetectors yield EQE >40%.

Semitransparent organic photovoltaics (OPV) possess unique properties that make them highly appealing for their integration into semitransparent architectonic elements such as windows or glazings. In order to provide sufficient transparency, non-opaque electrodes and thin photoactive layers are typically used, thus limiting the light-harvesting capacity. This can be partially overcome by using materials that absorb light mostly in the infrared region. On the other hand, the use of scalable techniques for the fabrication of semitransparent devices is often disregarded. In this work, we combine the blue, low-bandgap polymer PBTZT-stat-BDTT-8 with the near-infrared absorbing non-fullerene acceptor 4TICO, adapting the module fabrication to low-cost manufacturing processes that are compatible with large-scale production. Fully solution-processed semitransparent solar cells over 4.7% performance are prepared from non-chlorinated formulations, in air and using scalable techniques such as blade coating. Our prototypes of semitransparent laser-patterned OPV modules exceed 30% of transparency (measured as human perception transmittance, HPT) and yield efficiencies in the range of 4%, geometrical fill factors surpassing 90% and an active area above 1 cm². We verify the quality of cell-to-cell interconnection and optimise the geometry of the modules with the help of local optoelectronic imaging techniques. This work highlights the relevance of non-fullerene acceptors with strong absorption in the near-infrared, as they can meet industrial and technical requirements for the upscaling and integration of high-performance semitransparent OPV modules with low production costs.

By combining X-ray absorption fine structure and X-ray diffraction measurements with density functional and molecular dynamics simulations, we study the structure of a set of Ag_xBi_1−xS₂ nanoparticles, a materials system of considerable current interest for photovoltaics. An apparent contradiction between the evidence provided by X-ray absorption and diffraction measurements is solved by means of the simulations. We find that disorder in the cation sublattice induces strong local distortions, leading to the appearance of short Ag–S bonds, the overall lattice symmetry remaining close to hexagonal.

Copper nanoparticle inks have drawn much attention since they have the potential to constitute an alternative cost‐effective solution than other noble metals nanoparticle inks such as Ag for indium tin oxide (ITO)‐free printed electronic applications. Our research and development efforts have produced high conductivity copper nanoparticle inks which have excellent jetting and printing properties resulting in high quality inkjet‐printed (IJP) Cu nanoparticle‐based metal grids. We present ITO‐free, Si‐PCPDTBT: PC[70]BM organic photovoltaics (OPVs) processed in ambient low‐cost fabrication conditions comprising for the first time embedded and non embedded inkjet‐printed copper grid/Poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the bottom electrode with power conversion efficiencies (PCE) of 2.56 and 3.35%, respectively. The results of the ITO‐free OPVs using inkjet‐printed Cu nanoparticle current collecting grids are discussed relevant to reference ITO‐based OPVs with PCE of 4.92%.

We investigate the employment of carefully selected solvent additives in the processing of a commercial perovskite precursor ink and analyze their impact on the performance of organometal trihalide perovskite (CH₃NH₃PbI_3−xCl_x) photovoltaic devices. We provide evidence that the use of benzaldehyde can be used as an effective method to preserve the stoichiometry of the perovskite precursors in solution. Benzaldehyde based additive engineering shows to improve perovskite solid state film morphology and device performance of CH₃NH₃PbI_3−xCl_x based solar cells.

We report on solution processed polymer light emitting diodes (PLEDs) using inkjet-printed embedded and non-embedded metal grid anodes. Metal grids were inkjet-printed in a honeycomb layout. Honeycomb dimensions were varied from 3 mm to 8 mm to optimize device performance. Inkjet-printed grids were then coated with a highly conductive PEDOT:PSS formulation. First experiments on PEDOT:PSS coated, non-embedded metal grid anodes showed that grids with a 3 mm honeycomb diameter have a similar efficiency as optimized indium tin oxide (ITO) based reference devices. To further improve the efficiency of the devices, the honeycomb Ag-grids were embedded in an Ormocer^®-based material. A detailed performance analysis of PLEDs fabricated on ITO, non-embedded and embedded grids was carried out. It is shown that reduced leakage current and enhanced light outcoupling by embedding result in a significant efficiency enhancement of 250% in inkjet-printed embedded Ag-PEDOT:PSS ITO-free PLEDs, compared to the ITO-based reference PLEDs.