Pathways to Upscaling Highly Efficient Organic Solar Cells Using Green Solvents: A Study on Device Photophysics in the Transition from Lab-to-Fab.

As the rise of nonfullerene acceptors (NFA) has allowed lab-scale organic solar cells (OSC) to reach 20% efficiency, translating these devices into roll-to-roll compatible fabrication still poses many challenges for researchers. Among these are the use of green solvent solubility for large-scale manufacture, roll-to-roll compatible fabrication, and, not least, information on charge carrier dynamics in each upscaling step, to further understand the gap in performance. In this work, the reproducibility of champion devices using slot-die coating with 14% power conversion efficiency (PCE) is demonstrated, under the condition that the optimal thickness is maintained.

Quantifying Infiltration for Quality Control in Printed Mesoscopic Perovskite Solar Cells: A Microscopic Perspective.

Mesoscopic carbon-based perovskite solar cells (CPSCs) are often cited as a potential frontrunner to perovskite commercialization. Infiltration, the extent to which perovskite fills the mesoporous scaffold, is critical for optimum performance and stability. However, infiltration data are usually presented as qualitative photographic comparisons of samples with extreme infiltration variation.

Influences of Non-fullerene Acceptor Fluorination on Three-Dimensional Morphology and Photovoltaic Properties of Organic Solar Cells.

Fluorination of conjugated molecules has been established as an effective structural modification strategy to influence properties and has attracted extensive attention in organic solar cells (OSCs). Here, we have investigated optoelectronic and photovoltaic property changes of OSCs made of polymer donors with the non-fullerene acceptors (NFAs) ITIC and IEICO and their fluorinated counterparts IT-4F and IEICO-4F. Device studies show that fluorinated NFAs lead to reduced but increased and fill-factor (FF), and therefore, the ultimate influence to efficiency depends on the compensation of loss and gains of and FF.

Graphite-protected CsPbBr perovskite photoanodes functionalised with water oxidation catalyst for oxygen evolution in water.

Metal-halide perovskites have been widely investigated in the photovoltaic sector due to their promising optoelectronic properties and inexpensive fabrication techniques based on solution processing. Here we report the development of inorganic CsPbBr-based photoanodes for direct photoelectrochemical oxygen evolution from aqueous electrolytes. We use a commercial thermal graphite sheet and a mesoporous carbon scaffold to encapsulate CsPbBr as an inexpensive and efficient protection strategy.

Perovskite Photovoltaic Modules: Life Cycle Assessment of Pre-industrial Production Process.

Photovoltaic devices based on perovskite materials have a great potential to become an exceptional source of energy while preserving the environment. However, to enter the global market, they require further development to achieve the necessary performance requirements. The environmental performance of a pre-industrial process of production of a large-area carbon stack perovskite module is analyzed in this work through life cycle assessment (LCA).

On-Demand Electrical Switching of Antibody-Antigen Binding on Surfaces.

The development of stimuli-responsive interfaces between synthetic materials and biological systems is providing the unprecedented ability to modulate biomolecular interactions for a diverse range of biotechnological and biomedical applications. Antibody-antigen binding interactions are at the heart of many biosensing platforms, but no attempts have been made yet to control antibody-antigen binding in an on-demand fashion. Herein, a molecular surface was designed and developed that utilizes an electric potential to drive a conformational change in surface bound peptide moiety, to give on-demand control over antigen-antibody interactions on sensor chips.

Impact of Aggregation on the Photochemistry of Fullerene Films: Correlating Stability to Triplet Exciton Kinetics.

The photochemistry and stability of fullerene films is found to be strongly dependent upon film nanomorphology. In particular, PCBM blend films, dispersed with polystyrene, are found to be more susceptible to photobleaching in air than the more aggregated neat films. This enhanced photobleaching correlated with increased oxygen quenching of PCBM triplet states and the appearance of a carbonyl FTIR absorption band indicative of fullerene oxidation, suggesting PCBM photo-oxidation is primarily due to triplet-mediated singlet oxygen generation.

Facile self-assembly and stabilization of metal oxide nanoparticles.

This paper describes a facile method of self-assembling different metal oxide nanoparticles into nanostructured materials via di-carboxylate linkers (oxalic acid) using TiO2 as an example. In this method, the di-carboxylate linkers react with surface hydroxyls on metal oxide nanoparticles forming covalent, ester-like bonds, which enable the binding of two metal oxide particles, one at either end of the linker and facilitates efficient self-assembly of one group of metal oxide nanoparticles homogeneously distributed onto the surface of another group. The oxalate linkers can then be removed by thermal decomposition.

In situ monitoring and optimization of room temperature ultra-fast sensitization for dye-sensitized solar cells.

We describe the fastest dyeing of TiO2 photo-electrodes for dye-sensitized solar cells reported to date (<2 min) at room temperature giving η = 7.5% for an N719-SQ1-CDCA mixture which is significantly higher than devices dyed for >12 h using the same dye mixture (η = 5.5%).

A one-step low temperature processing route for organolead halide perovskite solar cells.

Organolead trihalide perovskite solar cells based upon the co-deposition of a combined Al2O3-perovskite layer at T < 110 °C are presented. We report an average PCE = 7.2% on a non-sintered Al2O3 scaffold in devices that have been manufactured from a perovskite precursor containing 5 wt% Al2O3 nanoparticles.

Ultra-fast dye sensitisation and co-sensitisation for dye sensitized solar cells.

We present a rapid (5 min) and controlled sensitisation method for dye sensitized solar cells which gives 6.0% for the Ru dye N719 and 3.7% for the IR absorbing squaraine SQ1.