organic solar cells elizabeth thomsen. organic semiconductors artist’s impression! semi conductor...
Post on 21-Dec-2015
221 views
TRANSCRIPT
![Page 1: Organic Solar Cells Elizabeth Thomsen. Organic Semiconductors Artist’s impression! Semi Conductor Organic](https://reader030.vdocuments.site/reader030/viewer/2022032521/56649d5a5503460f94a3adef/html5/thumbnails/1.jpg)
Organic Solar Cells
Elizabeth Thomsen
![Page 2: Organic Solar Cells Elizabeth Thomsen. Organic Semiconductors Artist’s impression! Semi Conductor Organic](https://reader030.vdocuments.site/reader030/viewer/2022032521/56649d5a5503460f94a3adef/html5/thumbnails/2.jpg)
Organic Semiconductors
Artist’s impression!
Semi Conductor
Organic
![Page 3: Organic Solar Cells Elizabeth Thomsen. Organic Semiconductors Artist’s impression! Semi Conductor Organic](https://reader030.vdocuments.site/reader030/viewer/2022032521/56649d5a5503460f94a3adef/html5/thumbnails/3.jpg)
Organic Semiconductors
Combine the virtues of plastics with those of semiconductors
High optical absorption coefficients
Properties tuned with flexible synthesis
Low cost fabrication
![Page 4: Organic Solar Cells Elizabeth Thomsen. Organic Semiconductors Artist’s impression! Semi Conductor Organic](https://reader030.vdocuments.site/reader030/viewer/2022032521/56649d5a5503460f94a3adef/html5/thumbnails/4.jpg)
Organic Solar Cells
Potential for medium efficiency, very low cost solar cells
![Page 5: Organic Solar Cells Elizabeth Thomsen. Organic Semiconductors Artist’s impression! Semi Conductor Organic](https://reader030.vdocuments.site/reader030/viewer/2022032521/56649d5a5503460f94a3adef/html5/thumbnails/5.jpg)
Organic Solar Cells
Absorption of photons to form excitons
Charge separation of excitons
Charge extraction of carriers
![Page 6: Organic Solar Cells Elizabeth Thomsen. Organic Semiconductors Artist’s impression! Semi Conductor Organic](https://reader030.vdocuments.site/reader030/viewer/2022032521/56649d5a5503460f94a3adef/html5/thumbnails/6.jpg)
Conjugated materials Polymers generally
insulating Alternating single and
double bonds (conjugated) π electrons able to
delocalise into clouds above and below the chain
Bandgap suitable for absorption of sunlight
![Page 7: Organic Solar Cells Elizabeth Thomsen. Organic Semiconductors Artist’s impression! Semi Conductor Organic](https://reader030.vdocuments.site/reader030/viewer/2022032521/56649d5a5503460f94a3adef/html5/thumbnails/7.jpg)
Active Layer Materials
Hole transporter
Electron transporter
Conjugated polymer
Conjugated dendrimer/
small molecule
Fullerenes
Nanocrystals
![Page 8: Organic Solar Cells Elizabeth Thomsen. Organic Semiconductors Artist’s impression! Semi Conductor Organic](https://reader030.vdocuments.site/reader030/viewer/2022032521/56649d5a5503460f94a3adef/html5/thumbnails/8.jpg)
Conjugated material: nanocrystal composites Typically nanocrystals synthesised separately to
polymer, then mixed Disadvantages
Nanocrystal surfactant inhibits charge transfer Co-solvents required for mixing: can adversely affect
nanocrystal solubility and polymer chain orientation One-pot synthesis of conjugated polymer:
nanocrystal composite developed by Watt et al. Extended this synthesis to a conjugated oligomer
and a dendrimer
![Page 9: Organic Solar Cells Elizabeth Thomsen. Organic Semiconductors Artist’s impression! Semi Conductor Organic](https://reader030.vdocuments.site/reader030/viewer/2022032521/56649d5a5503460f94a3adef/html5/thumbnails/9.jpg)
Conjugated small molecule: nanocrystal composite
OligomerCadmium acetate
Toluene DMSO
110°C
Sulphur flakes in toluene Oligomer:
CdS in chloro-benzene
Dendrimer
Oligomer
PbS CdS
![Page 10: Organic Solar Cells Elizabeth Thomsen. Organic Semiconductors Artist’s impression! Semi Conductor Organic](https://reader030.vdocuments.site/reader030/viewer/2022032521/56649d5a5503460f94a3adef/html5/thumbnails/10.jpg)
Oligomer: CdS
![Page 11: Organic Solar Cells Elizabeth Thomsen. Organic Semiconductors Artist’s impression! Semi Conductor Organic](https://reader030.vdocuments.site/reader030/viewer/2022032521/56649d5a5503460f94a3adef/html5/thumbnails/11.jpg)
CdS Rods
![Page 12: Organic Solar Cells Elizabeth Thomsen. Organic Semiconductors Artist’s impression! Semi Conductor Organic](https://reader030.vdocuments.site/reader030/viewer/2022032521/56649d5a5503460f94a3adef/html5/thumbnails/12.jpg)
Final thoughts
Grew PbS and CdS nanocrystals in oligomer, PbS nanocrystals in dendrimer
Highly likely the synthesis can be generalised to a variety of conjugated soluble small molecule: nanocrystal systems
Combination of materials extends the absorption spectrum
Direct interaction between the small molecule and the nanocrystal is likely to enable efficient charge separation
Shape control of nanoparticles may improve charge transfer through the device
![Page 13: Organic Solar Cells Elizabeth Thomsen. Organic Semiconductors Artist’s impression! Semi Conductor Organic](https://reader030.vdocuments.site/reader030/viewer/2022032521/56649d5a5503460f94a3adef/html5/thumbnails/13.jpg)
Acknowledgements
Alexandros Stravinadis Andrew Watt
Thankyou for listening!