Umeå University's logo

umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Tunable two-dimensional patterning of a semiconducting Nanometer-Thin C60 fullerene film using a spatial light modulator
Umeå University, Faculty of Science and Technology, Department of Physics.ORCID iD: 0000-0001-7493-6838
Umeå University, Faculty of Science and Technology, Department of Physics.
Umeå University, Faculty of Science and Technology, Department of Physics.ORCID iD: 0000-0001-5475-1422
Umeå University, Faculty of Science and Technology, Department of Physics.ORCID iD: 0000-0003-1274-5918
Show others and affiliations
2020 (English)In: ACS Applied Nano Materials, ISSN 2574-0970, Vol. 3, no 6, p. 2574-0970Article in journal (Other academic) Published
Abstract [en]

The photochemical coupling of fullerene molecules into covalently connected oligomeric or polymeric structures can result in drastically lowered solubility in common solvents with retained semiconductor properties. Here, we exploit this combination of properties for the utilization of fullerenes as a negative photoresist material with electronic functionality. Specifically, we develop an easily tunable exposure system, essentially comprising a laser and a computer-controlled spatial light modulator (SLM) featuring >8 million independently controlled pixels, for the spatially selective photochemical transformation of nanometer-thin C60 fullerene films. With a carefully designed laser-SLM-exposure/solvent-development cycle, we are able to realize well-resolved two-dimensional hexagonal or square patterns of circular C60 microdots with a center-to-center distance of 1–5 μm and a maximum thickness of 20–35 nm over several square-millimeter-sized areas on a substrate. The functionality of such a hexagonal C60 pattern was demonstrated by its inclusion in between the transparent electrode and the active material in a light-emitting electrochemical cell, which featured an enhanced light output by >50% in comparison to a reference device void of the patterned C60 layer.

Place, publisher, year, edition, pages
Acoustical Society of America (ASA), 2020. Vol. 3, no 6, p. 2574-0970
Keywords [en]
C60, fullerenes, tunable and high-resolution 2D patterning, spatial light modulator, negative photoresist, light outcoupling, light-emitting electrochemical cell
National Category
Other Physics Topics
Identifiers
URN: urn:nbn:se:umu:diva-166406DOI: 10.1021/acsanm.0c00793ISI: 000545689000055Scopus ID: 2-s2.0-85087440615OAI: oai:DiVA.org:umu-166406DiVA, id: diva2:1378923
Part of project
The light-emitting electrochemical cell: Developing rational design principles for efficient, bright and green operation, Swedish Research Council
Funder
Swedish Foundation for Strategic Research Swedish Research CouncilSwedish Energy AgencyBertil & Britt Svenssons Stiftelse för Belysningsteknik
Note

Previously included in thesis in manuscript form.

Available from: 2019-12-16 Created: 2019-12-16 Last updated: 2023-03-23Bibliographically approved
In thesis
1. Structure and morphology control of organic semiconductors for functional optoelectronic applications
Open this publication in new window or tab >>Structure and morphology control of organic semiconductors for functional optoelectronic applications
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The functionality and application of organic semiconductors are largely dependent on their constituent structure and morphology. This thesis presents a number of functional and novel approaches for the control and tuning of structural and morphological features of a variety of organic semiconductor materials, and also demonstrates that these approaches can be utilized for improved device operation of field-effect transistors, organic solar cells and light-emitting electrochemical cells.

The fullerene family is a particular group of closed-cage organic semiconductors, which can be photochemically coupled into larger dimeric or polymeric structures through the excitation of the fullerene molecules by light emission. In Paper I, we perform a detailed experimental and analytical investigation, which demonstrates that this photochemical monomer-to-dimer transformation requires that both constituent fullerene molecules are photoexcited. The direct consequence is that the initial probability for the photochemical transformation is dependent on the square of the light-emission intensity.

The photochemical coupling of fullerene molecules commonly results in a distinctly lowered solubility in common hydrophobic solvents, which can be utilized for the direct patterning of fullerene films by resist-free lithography. In Paper II, we utilize this patterning opportunity for the fabrication of one-dimensional fullerene nano-stripes using two-beam laser interference lithography. A desired high contrast between the patterned and non-patterned fullerene regions is facilitated by the non-linear response of the photochemical transformation process, as predicted by the findings in Paper I. The patterned fullerene nano-stripes were utilized as the active material in field-effect transistors, which featured high electron mobility and large on-off ratio.

This patterning was in Paper III extended into easy tunable two-dimensional fullerene structures by the design and development of an exposure setup, essentially comprising a laser and a spatial light modulator featuring >8 millions of independently controlled mirrors. With this approach, we could fabricate well-defined fullerene microdots over a several square-millimeter sized area, which was utilized as an internal out-coupling layer in a light-emitting electrochemical cell with significantly enhanced light output.

Paper IV reports on the development of a new “spray-sintering” method for the cost-efficient solution-based deposition of the active material in light-emitting electrochemical cells. This carefully designed approach effectively resolves the issue with phase separation between the hydrophobic organic semiconductor and the hydrophilic electrolyte that results in a sub-par LEC performance, and also allows for the direct fabrication of LEC devices onto complex surfaces, including a stainless-steel fork.

Paper V finally reports on the design and synthesis of a soluble small molecule, featuring a donor-acceptor-donor configuration. It acts as the donor when combined with a soluble fullerene acceptor in the active material of organic solar cells, and such devices with optimized donor/acceptor nanomorphology feature a high open-circuit voltage of ~1.0 V during solar illumination.

Place, publisher, year, edition, pages
Umeå: Umeå University, 2019. p. 65
Keywords
Organic electronics, organic photonics, patterning, fullerene, polymerization, dimerization, spray-deposition, morphology, small molecule donor, high open-circuit voltage
National Category
Polymer Technologies Nano Technology Other Physics Topics Condensed Matter Physics
Identifiers
urn:nbn:se:umu:diva-166407 (URN)978-91-7855-170-5 (ISBN)978-91-7855-169-9 (ISBN)
Public defence
2020-01-09, Bio.A.206, Biologihuset, Umeå, 09:00 (English)
Opponent
Supervisors
Available from: 2019-12-19 Created: 2019-12-16 Last updated: 2019-12-17Bibliographically approved
2. KNOW YOUR ENEMY: Characterizing Pathogenic Biomaterials Using Laser Tweezers
Open this publication in new window or tab >>KNOW YOUR ENEMY: Characterizing Pathogenic Biomaterials Using Laser Tweezers
2022 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Diseases caused by pathogenic agents such as bacteria and viruses result in devastating costs on personal and societal levels. However, it is not just the emergence of new diseases that is problematic. Antibiotic resistance among bacteria makes uncomplicated infections difficult and lethal. Resilient disease-causing spores spread in hospitals, the food industry, and water supplies requiring effective detection and disinfection methods. Further, we face complex neurological diseases where no effective treatment or diagnostic methods exist. Thus, we must increase our fundamental understanding of these diseases to develop effective diagnostic, detection, disinfection, and treatment methods.

Classically, the methods used for detecting and studying the underlying mechanics of pathogenic agents work on a large scale, measuring the average macroscopic behavior and properties of these pathogens. However, just as with humans, the average behavior is not always representative of individual behavior. Therefore, it is also essential to investigate the characteristics of these pathogens on a single cell or particle level. 

This thesis develops and applies optical techniques to characterize pathogenic biomaterial on a single cell or particle level. At the heart of all these studies is our Optical Tweezers (OT) instrument. OT are a tool that allows us to reach into the microscopic world and interact with it. Finally, by combining OT with other experimental techniques, we can chemically characterize biomaterials and develop assays that mimic different biological settings. Using these tools, we investigate bacterial adhesion, disinfection, and detection of pathogenic spores and proteins.

Hopefully, the insights of these studies can lessen the burden on society caused by diseases by helping others develop effective treatment, diagnostic, detection, and disinfection methods in the future. 

Place, publisher, year, edition, pages
Umeå: Umeå universitet, 2022. p. 73
Keywords
Optical Tweezers, Laser Tweezers, Raman Spectroscopy, Bacterial Adhesion, Biophysics, Pili, Bacterial Spores, Endospores, Oocysts, Cryptosporidium, Optics
National Category
Biophysics Atom and Molecular Physics and Optics
Research subject
biology; Physics
Identifiers
urn:nbn:se:umu:diva-192471 (URN)978-91-7855-726-4 (ISBN)978-91-7855-727-1 (ISBN)
Public defence
2022-03-11, NAT.D.410, Naturvetarhuset, Umeå, 09:00 (English)
Opponent
Supervisors
Available from: 2022-02-18 Created: 2022-02-14 Last updated: 2022-02-15Bibliographically approved

Open Access in DiVA

fulltext(5404 kB)182 downloads
File information
File name FULLTEXT01.pdfFile size 5404 kBChecksum SHA-512
eec97820c23eff50520cd88b98df5ea3c06b46f336260d56a2bacd5e1fa2a489a52f98272ad039611c1cf5c7ca4fd0494f03dc18fe49039f9d0f76e48db8453c
Type fulltextMimetype application/pdf

Other links

Publisher's full textScopus

Authority records

Enevold, JennyDahlberg, TobiasStangner, TimTang, ShiLindh, E. MattiasGracia-Espino, EduardoAndersson, MagnusEdman, Ludvig

Search in DiVA

By author/editor
Enevold, JennyDahlberg, TobiasStangner, TimTang, ShiLindh, E. MattiasGracia-Espino, EduardoAndersson, MagnusEdman, Ludvig
By organisation
Department of Physics
Other Physics Topics

Search outside of DiVA

GoogleGoogle Scholar
Total: 182 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 1036 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf