Change search
ReferencesLink to record
Permanent link

Direct link
Relaxation is the key to longer life: suppressed degradation of P3HT films on conductive substrates
KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF. SP Tech Res Inst Sweden, Chem Mat & Surfaces Unit, Sweden.
KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
Show others and affiliations
2014 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 2, no 33, 13270-13276 p.Article in journal (Refereed) Published
Abstract [en]

Here we show the dependence of the degree of degradation of poly-3-hexylthiophene (P3HT) films on the conductivity of the supporting substrate. P3HT is widely used for organic solar cells and electronic devices because it allows simple, low cost fabrication and has potential for the fabrication of flexible devices. However, P3HT is known to have a relatively low photostability, and investigating the photodegradation mechanism is an active research field. We find that P3HT films on conductive substrates show significantly retarded degradation and retain their chemical and morphological features when compared to similar films on glass substrates. This 'substrate effect' in retarding the degradation of P3HT films is evident even upon prolonged exposure to air for up to five months.

Place, publisher, year, edition, pages
2014. Vol. 2, no 33, 13270-13276 p.
National Category
Other Materials Engineering Other Physics Topics
URN: urn:nbn:se:kth:diva-150905DOI: 10.1039/c4ta02345eISI: 000340514500011ScopusID: 2-s2.0-84905169082OAI: diva2:746800
Swedish Foundation for Strategic Research , EM11-0002

QC 20140915

Available from: 2014-09-15 Created: 2014-09-11 Last updated: 2016-05-19Bibliographically approved
In thesis
1. Semiconducting Polymer Nanofibers and Quantum Dot based Nanocomposites for Optoelectronic Applications
Open this publication in new window or tab >>Semiconducting Polymer Nanofibers and Quantum Dot based Nanocomposites for Optoelectronic Applications
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Nanostructured materials have attracted a broad interest in various technologies such as optoelectronics. In this thesis, nanostructured semiconductor nanocrystals, including inorganic and organic materials, were fabricated by solution based methods. The reaction conditions were optimized to control the size and morphology of the obtained nanocrystals. The optical and photoelectric properties of nanocrystals were evaluated for potential optoelectronic applications.

Colloidal CdSe quantum dots (QDs) were synthesized via thermolysis method and layers of CdS was further grown on the core CdSe QDs to form a core-shell heterostructure quantum dots (HQDs). The optical properties of HQDs were evaluated and showed the characteristics of quasi-type-II alignment of energy levels, which has potential for excitonic solar cell (XSC) application.

Nanofibers of the semiconducting polymer poly-(3-hexylthiophene) (P3HT) were synthesized via a modified whisker method. In order to control the size (both the length and the diameter) of nanofibers, we systematically studied the ratio between mixture solvents and the solute concentration. In addition, the degradation processes of P3HT nanofibers on different substrates under various environments were investigated. We found that the degradation of P3HT nanofibers can be effectively suppressed by using the substrate of higher conductivity. A nanocomposite consisting of HQDs and P3HT nanofibers was fabricated and its photoelectric properties were evaluated by I-V measurements. A ‘turn-on’ voltage was found and revealed the localization of excited holes within the HQDs, which confirmed the quasi-type-II alignment between core and shell energy levels.

In addition, we aligned the P3HT nanofibers by applying the external electric field. Alternating current (AC) and direct current (DC) induced alignments of P3HT nanofibers were investigated respectively to study the effects of different electric fields on the alignment behavior. It was determined that the AC electric field allowed a better alignment of nanofibers. Moreover, two different lengths of P3HT nanofibers were aligned and their absorption spectra were measured. Under polarized light beams, we observed a better aligned pattern in the case of longer nanofibers, shown as a higher dichroic ratio calculated from optical absorption spectra. These aligned nanofibers may find applications in optoelectronic devices.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2016. 57 p.
National Category
Nano Technology
Research subject
urn:nbn:se:kth:diva-187255 (URN)978-91-7595-946-7 (ISBN)
Public defence
2016-06-15, Sal C, Electrum, Isafjordsgatan 26, Stockholm, 10:00 (English)

QC 20160519

Available from: 2016-05-19 Created: 2016-05-18 Last updated: 2016-05-20Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Zhao, YichenSugunan, AbhilashSchmidt, TorstenToprak, Muhammet S.Muhammed, Mamoun
By organisation
Material Physics, MFFunctional Materials, FNM
In the same journal
Journal of Materials Chemistry A
Other Materials EngineeringOther Physics Topics

Search outside of DiVA

GoogleGoogle Scholar
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

Altmetric score

Total: 36 hits
ReferencesLink to record
Permanent link

Direct link