The emerging field of printed electronics uses large amounts of printing and coating solvents during fabrication, which commonly are deposited and evaporated within spaces available to workers. It is in this context unfortunate that many of the currently employed solvents are non-desirable from health, safety, or environmental perspectives. Here, we address this issue through the development of a tool for the straightforward identification of functional and “green” replacement solvents. In short, the tool organizes a large set of solvents according to their Hansen solubility parameters, ink properties, and sustainability descriptors, and through systematic iteration delivers suggestions for green alternative solvents with similar dissolution capacity as the current non-sustainable solvent. We exemplify the merit of the tool in a case study on a multi-solute ink for high-performance light-emitting electrochemical cells, where a non-desired solvent was successfully replaced by two benign alternatives. The green-solvent selection tool is freely available at: www.opeg-umu.se/green-solvent-tool.

Polymer light-emitting electrochemical cells (LECs) are inherently dependent on a suitable electrolyte for proper function.Here, we design and synthesize a series of alkyl carbonate-capped starbranched oligoether-based electrolytes with large electrochemical stability windows, facile ion release, and high compatibility with common light-emitting materials. LECs based on such designed electrolytes feature fast turn-on, a long operational lifetime of 1400 h at >100 cd m −2 and a record-high power conversion efficiency of 18.1 lm W −1 , when equipped with an external outcoupling film.

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Metal–organic frameworks (MOFs) have attracted intensive study as solid electrolytes (SEs) in recent years. However, MOF particles work separately in SEs and numerous interfaces hinder a high-efficiency ion transport, which lowers the performance of solid-state batteries (SSBs). Herein, continuous ion-conductive paths were constructed by cross-linked MOF chains. Chains of a newly developed MOF (Zr-BPDC-2SO3H) were grown on bacterial cellulose (BC) nanofibers to provide a continuous ion transport network. The cross-linked MOF chains exhibit a high ionic conductivity of 7.88 × 10–4 S cm–1 at 25 °C, single-ion transport ability (t Li +=0.88), a wide electrochemical window up to 5.10 V, excellent interface compatibility, and the capability for suppressing lithium dendrites. Most importantly, the SSB fabricated with the cross-linked MOF chains shows more than 100% improved specific capacity in comparison to an SSB without this design and stable cycling performance at 3 C. This work provides a splendid strategy for developing high-performance SEs with porous ion conductors.

Experimental fi ndings and associated theoretical insights regarding the photochemical transformation of fullerenes are reported, which challenge the conventional wisdom in the fi eld and point out a viable path towards improved fullerene-based electronic devices. It is shown that the effi ciency of the photochemical monomer-to-dimer transformation of the fullerene [6,6 ′ ]-phenyl-C 61 -butyric acid methyl ester (PCBM) is strongly dependent on the light intensity, and this is utilized to demonstrate that direct patterning of an electroactive PCBM fi lm can be effectuated by sub-second UV-light exposure followed by development in a tuned developer solution. By straightforward analytical reasoning, it is demonstrated that the observed intensitydependent monomer-to-dimer transformation dictates that a signifi cant back-reaction to the ground state must be in effect, which presumably originates from the excited-triplet state. By a combination of numerical modeling and analytical argumentation, it is further shown that the fi nal dimer formation must constitute a bi-excited reaction between two neighboring monomers photo-excited to the triplet state.

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We utilize UV light for the attainment of high‐resolution, electronically active patterns in [6,6]‐phenyl C61‐butyric acid methyl ester (PCBM) films. The patterns are created by directly exposing selected parts of a solution‐cast PCBM film to UV light, and thereafter developing the film by immersing it in a tuned developer solution. We demonstrate that it is possible to attain complex, large‐area PCBM structures with a smallest demonstrated‐feature size of 1 μm by this method, and that the patterned PCBM material exhibits a high average electron mobility (1.2 × 10−2 cm2 V−1 s−1) in transistor experiments. The employment of UV light for direct patterning of PCBM for electronic applications is attractive, because PCBM exhibits high absorption in the UV range, and no sacrificial photoresist is needed. The patterning is achieved through the transformation by UV light of the soluble PCBM monomers into insoluble dimers with retained attractive electronic properties.

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