| 1. |
- Bergqvist, Jonas, et al.
(author)
-
Sub-glass transition annealing enhances polymer solar cell performance
- 2014
-
In: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488. ; 2:17, s. 6146-6152
-
Journal article (peer-reviewed)abstract
- Thermal annealing of non-crystalline polymer: fullerene blends typically results in a drastic decrease in solar cell performance. In particular aggressive annealing above the glass transition temperature results in a detrimental coarsening of the blend nanostructure. We demonstrate that mild annealing below the glass transition temperature is a viable avenue to control the nanostructure of a non-crystalline thiophene-quinoxaline copolymer: fullerene blend. Direct imaging methods indicate that coarsening of the blend nanostructure can be avoided. However, a combination of absorption and luminescence spectroscopy reveals that local changes in the polymer conformation as well as limited fullerene aggregation are permitted to occur. As a result, we are able to optimise the solar cell performance evenly across different positions of the coated area, which is a necessary criterion for large-scale, high throughput production.
|
|
| 2. |
- Bergqvist, J., et al.
(author)
-
Sub-glass transition annealing enhances polymer solar cell performance
- 2014
-
In: Journal of Materials Chemistry A. - 2050-7488 .- 2050-7496. ; 2:17, s. 6146-6152
-
Journal article (peer-reviewed)abstract
- Thermal annealing of non-crystalline polymer:fullerene blends typically results in a drastic decrease in solar cell performance. In particular aggressive annealing above the glass transition temperature results in a detrimental coarsening of the blend nanostructure. We demonstrate that mild annealing below the glass transition temperature is a viable avenue to control the nanostructure of a non-crystalline thiophene–quinoxaline copolymer:fullerene blend. Direct imaging methods indicate that coarsening of the blend nanostructure can be avoided. However, a combination of absorption and luminescence spectroscopy reveals that local changes in the polymer conformation as well as limited fullerene aggregation are permitted to occur. As a result, we are able to optimise the solar cell performance evenly across different positions of the coated area, which is a necessary criterion for large-scale, high throughput production.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Diaz de Zerio Mendaza, Amaia, 1986, et al.
(author)
-
Neat C60:C70 buckminsterfullerene mixtures enhance polymer solar cell performance
- 2014
-
In: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 2:35, s. 14354-14359
-
Journal article (peer-reviewed)abstract
- We demonstrate that bulk-heterojunction blends based on neat, unsubstituted buckminsterfullerenes (C60, C70) and a thiophene–quinoxaline copolymer (TQ1) can be readily processed from solution. Atomic force and transmission electron microscopy as well as photoluminescence spectroscopy reveal that thin films with a fine-grained nanostructure can be spin-coated, which display a good photovoltaic performance. Replacement of substituted fullerenes with C60 or C70 only results in a small drop in open-circuit voltage from 0.9 V to about 0.8 V. Thus, a power conversion efficiency of up to 2.9% can be maintained if C70 is used as the acceptor material. Further improvement in photovoltaic performance to 3.6% is achieved, accompanied by a high internal quantum efficiency of 75%, if a 1 : 1 C60:C70 mixture is used as the acceptor material, due to its improved solubility in ortho-dichlorobenzene.
|
|
| 8. |
- Henriksson, Patrik, 1983, et al.
(author)
-
Stability study of quinoxaline and pyrido pyrazine based co-polymers for solar cell applications
- 2014
-
In: Solar Energy Materials and Solar Cells. - : Elsevier BV. - 0927-0248 .- 1879-3398. ; 130, s. 138-143
-
Journal article (peer-reviewed)abstract
- We present two co-polymer families; one based on a thiophene-quinoxaline unit and one on a thiophene-pyrido pyrazine unit. Co-polymerization of these monomers with thiophene-hexylthiophene was performed to create polymers with an optical absorption that fully covers the visible part of the solar spectrum with the aim to enhance the solar cell performances of these polymers. We have also studied how increasing the fraction of thiophene-hexylthiophene affects the photo-oxidative stability of these polymers. Thiophene-pyrido pyrazine solar cells displayed increased device efficiency upon addition of the thiophene-hexylthiophene and, in addition, the stability is retained upon inclusion of these units. In contrast, we found that for the thiophene-quinoxaline based co-polymer, both device efficiency and stability decreased with increasing thiophene-hexylthiophene fraction. Moreover, our results indicate that the photo-oxidative stability of the thiophene-quinoxaline co-polymer is independent of the polymer molecular weight as well as of the film thickness.
|
|
| 9. |
- Lindqvist, Aron, 1964-, et al.
(author)
-
Assessment of the severity of injuries to hands by powered wood splitters
- 2010
-
In: Journal of Plastic Surgery and Hand Surgery. - 2000-6764. ; 44:4-5, s. 237-244
-
Journal article (peer-reviewed)abstract
- Our aim was to rate the severity of injuries to hands by powered wood splitters. The patients were identified from a computerised registry and the cause of injury was confirmed by written questionnaire and structured telephone interview. Information about the anatomy of the injuries was gathered from patients’ records and radiographs. Severity of injury was rated according to the Hand Injury Severity Scoring System (HISS system) and the Injury Severity Score (ISS). The reliability of HISS rating was tested. The mean Hand Injury Severity Score (HISS) was 63 and the mean ISS was 3.7. Twenty-five (19 %) of patients had minor, 41 (31 %) had moderate, 30 (23 %) had severe, and 35 (27 %) had major injuries when scored by the HISS system. Children’s injuries were more severe than those of adults. There was no difference in severity between injuries made by wedge and screw splitters. It is not possible to avoid serious hand injuries from powered wood splitters completely by prohibiting one of the two main types of splitter.
|
|
| 10. |
- Lindqvist, Aron, 1964-, et al.
(author)
-
DASH and Sollerman test scores after hand injury from powered wood splitters
- 2011
-
In: Journal of Hand Surgery, European Volume. - : SAGE Publications. - 1753-1934 .- 2043-6289. ; 36E:1, s. 57-61
-
Journal article (peer-reviewed)abstract
- The purpose of the study was to describe the outcome after hand injury from powered wood splitters, and to investigate the relation between injury severity and outcome. Injury severity was rated according to the Hand Injury Severity Scoring System (HISS system) and the Injury Severity Score method. The patients were evaluated with the Disabilities of the Arm Shoulder and Hand outcome questionnaire (DASH), and 26 of the most severely injured patients were evaluated with the Sollerman test. The mean DASH score was moderately elevated at 15, indicating that many of these patients have sequelae. A statistically significant correlation between HISS and DASH scores was found, implying that initial injury severity is of importance for outcome. The mean Sollerman score in the injured hand was 66, which amounts to a significantly impaired hand function.
|
|
