Beyond the Threshold: A Study of Chalcogenophene-Based Two-Photon Initiators

Lunzer, Markus; Beckwith, Joseph S.; Chalupa-Gantner, Franziska; Rosspeintner, Arnulf; Licari, Giuseppe; Steiger, W.; Hametner, Christian; Liska, Robert; Fröhlich, Johannes; Vauthey, Eric; Ovsianikov, Aleksandr; Holzer, Brigitte

doi:10.1021/acs.chemmater.1c04002

Cited by 21 publications

(15 citation statements)

References 85 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For each formulation, Figure S4 shows a typical transmitted micrograph of each μ-structure with its corresponding writing speed. According to such a qualitative screening test previously proposed by Liska et al , − it can be inferred that the photoresist with XCAR authorizes a maximum writing speed of about 400 μm s –1 , which is ∼1.8-fold higher than that measured for ACAR formulation in the same conditions. In order to compare more precisely the 2PP performances of ACAR and XCAR , we have also evaluated the polymerization energy threshold ( E th ) of their respective isomolar photoresists.…”

Section: Resultsmentioning

confidence: 90%

Reversible Optical Data Storage via Two-Photon Micropatterning of o-Carboranes-Embedded Switchable Materials

et al. 2023

View full text Add to dashboard Cite

Two-photon polymerization (2PP) constitutes a powerful lighttriggered 3D stereolithography, allowing the fabrication of micro-or nanostructures with spatially encoded functionalities. In the present report, we take advantage of this programmable property in order to develop a photoresist authorizing the direct 2PP-lithography of luminescent switchable μ-structures. In this single step processing method, we highlight the pivotal role of a quadrupolar o-caborane initiator comprising a 9, 10-disubstituted anthracene core capable of chemically entrap oxygen-inhibiting species during the free radical two-photon initiation step. Such an O 2 sequestration approach not only enhances the twophoton initiation performance of the polymerization, but also generates a nonluminescent endoperoxide by-product embedded in the polymerized macrostructure. Interestingly, simple heating of the final materials promotes endoperoxide thermolysis, resulting in the recovery of the luminescent ocarborane dye. This original luminescence turn OFF/ON property exhibits excellent fatigue resistance through a large number of alternated thermal and light stimuli cycles. The potential of this direct laser writing strategy for reversible data storage applications is finally demonstrated by the two-photon patterning of a series of matricially organized μ-structures used as rewritable binary optical memories which can be easily encoded on demand.

show abstract

Section: Resultsmentioning

confidence: 90%

Reversible Optical Data Storage via Two-Photon Micropatterning of o-Carboranes-Embedded Switchable Materials

et al. 2023

View full text Add to dashboard Cite

show abstract

“…Two-Photon Polymerization: 2PP 3D printed parts were fabricated using a NanoOne 1000 high-resolution 3D printing system (UpNano GmbH, Austria) in vat mode. [39] Here, the laser (80 MHz repetition rate, 90 fs pulse length, and 780 nm wavelength) was focused through a highprecision cover glass into a material vat containing the resin and maintained at a constant height above the glass window. For layer-wise 3D structuring, the laser was scanned along the xy plane by a galvanometer scanner, and the objective together with the vat is lowered along the z axis using a piezo stage.…”

Section: Methodsmentioning

confidence: 99%

Overcoming the Transport Limitations of Photopolymer‐Derived Architected Carbon

Baglo

Sauermoser

Lid

et al. 2023

Adv Materials Technologies

Self Cite

View full text Add to dashboard Cite

Photopolymer derived carbon grows in popularity, yet the range in available feature sizes is limited. Here the focus is on expanding the field to low surface to volume ratio (SVR) structures. A high temperature acrylic photopolymerizable precursor with FTIR and DSC is described and a thermal inert‐gas treatment is developed for producing architected carbon in the mm scale with SVR of 1.38×10−3 µm−1. Based on thermogravimetric analysis and mass spectrometry, two thermal regimes with activation energies of ≈79 and 169 kJ mol−1 are distiguished, which is reasoned with mechanisms during the polymer's morphologic conversion between 300 and 500 °C. The temperature range of the major dimensional shrinkage (300–440 °C, 50%) does not match the range of the largest alteration in elemental composition (440–600 °C, O/C 0.25–0.087%). The insights lead to an optimized thermal treatment with an initial ramp (2 °C min−1 to 350 °C), isothermal hold (14 h), post hold ramp (0.5 °C min−1 to 440 °C) and final ramp (10 °C min−1 to 1000 °C). The resulting carbon structures are dimensionally stable, non‐porous at the µm scale, and comprise an unprecedented variation in feature sizes (from mm to µm scale). The findings shall advance architected carbon to industrially relevant scales.

show abstract

“…Two-photon initiator (TPI) plays a crucial role for the photosensitivity among all the components of photoresist. In this respect, the development of high-efficiency TPI can also implement the speeding up of two-photon lithography. − 7-Diethylamino-3-thenoylcoumarin (DETC), which holds multiple advantages of high molar extinction coefficients, high intersystem crossing coefficients, and excellent resin compatibility, has been widely employed as a commercial TPI in two-photon lithography. , DETC falls into the category of keto-coumarins, which are generally utilized as triplet-sensitizers and photoinitiators. In DCM, the two-photon absorption cross section and fluorescence quantum yield of DETC are 82 GM and 52% (Table ), respectively.…”

Section: Introductionmentioning

confidence: 99%

Ketocoumarin-Based Photoinitiators for High-Sensitivity Two-Photon Lithography

Jin

Shen

et al. 2023

ACS Appl. Polym. Mater.

View full text Add to dashboard Cite

Ketocoumarins are attractive and distinct photosensitizers due to their high molar extinction coefficients, high intersystem crossing coefficients, and high photochemical stability. As a classic commercial ketocoumarin-based two-photon initiator, 7-diethylamino-3-thenoylcoumarin (DETC) was widely used in two-photon lithography. However, the large fluorescence quantum yield and low twophoton absorption cross section value greatly limit its application in high-throughput nanofabrication. In this work, a series of DETC derivatives were developed by extending the length of the alkyl chain and integrating different donor and acceptor groups. These ketocoumarin-based initiators, namely, compounds 1−7, were designed, synthesized, and unambiguously characterized. Compared with DETC, these compounds exhibit higher molar extinction coefficient, lower fluorescence quantum yield, higher two-photon absorption cross section, and improved sensitivity in two-photon lithography. Among these molecules, compound 7 with expanded π-electron systems and structures with enhanced intramolecular charge transfer exhibits the best sensitivity in two-photon lithography. With compound 7-based photoresist, many kinds of complex threedimensional patterns can be fabricated using two-photon lithography at a writing speed of up to 60 mm s −1 . The high two-photon initiation sensitivity makes these compounds promising candidates for commercialization and provides a new design concept for the development of new initiators.

show abstract

Beyond the Threshold: A Study of Chalcogenophene-Based Two-Photon Initiators

Cited by 21 publications

References 85 publications

Reversible Optical Data Storage via Two-Photon Micropatterning of o-Carboranes-Embedded Switchable Materials

Reversible Optical Data Storage via Two-Photon Micropatterning of o-Carboranes-Embedded Switchable Materials

Overcoming the Transport Limitations of Photopolymer‐Derived Architected Carbon

Ketocoumarin-Based Photoinitiators for High-Sensitivity Two-Photon Lithography

Contact Info

Product

Resources

About