uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Optoelectronic properties of p-i-n heterojunctions based on germanium nanocrystals
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
Show others and affiliations
2013 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 114, no 3, 033510- p.Article in journal (Refereed) Published
Abstract [en]

We investigated the possibility of using physical vapour deposited Ge nanocrystals (NCs) in optoelectronic devices such as solar cells. We have prepared p-i-n heterojunctions based on p(+)-doped Si substrate/undoped Ge NCs/ZnO: Al layer stacks and their optoelectronic properties were characterised. Under light, the generation of photo-carriers from the Ge NCs themselves was demonstrated. The photovoltaic behaviour of the p-i-n structure was also highlighted, with a measured Voc of 224 mV compared to 580 mV in theory. The discrepancy between theory and experiment was discussed on the basis of TEM observations, optical and carrier generation measurements as well as modelling.

Place, publisher, year, edition, pages
2013. Vol. 114, no 3, 033510- p.
National Category
Natural Sciences Engineering and Technology
Research subject
Engineering Science with specialization in Materials Science
URN: urn:nbn:se:uu:diva-208385DOI: 10.1063/1.4813616ISI: 000322202700025OAI: oai:DiVA.org:uu-208385DiVA: diva2:652194
Available from: 2013-09-30 Created: 2013-09-30 Last updated: 2016-06-15Bibliographically approved
In thesis
1. Electron tomography analysis of 3D order and interfacial structure in nano-precipitates
Open this publication in new window or tab >>Electron tomography analysis of 3D order and interfacial structure in nano-precipitates
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Structural characterization is essential to understand the formation mechanisms of the nanostructures in thin absorber layers in third generation solar cells and amyloid protein aggregates. Since to the dimension of the precipitated structures is in nanometer scale, electron tomography technique in transmission electron microscopy (TEM) has been applied as a major tool to analyze the 3D order and distribution of precipitates using the electron tomography technique. 

Silicon rich silicon carbide (SRSC) films were deposited by plasma enhanced chemical vapor deposition (PECVD) technique and annealed in the nitrogen atmosphere for 1 hour at 1100 °C. The spectrum-imaging (SI) technique in Energy filtered TEM (EFTEM) imaging mode was used to develop electron tomography. From the reconstructed sub-volumes, the complex, three dimensional interfacial nanostructure between the precipitated NPs and their parental matrix was observed and explained in terms of thermodynamic concepts. Additionally, the feasibility of raw data 4D electron tomography has been demonstrated using the EFTEM SI dataset.

The aggregation process of the human islet amyloid polypeptide (hIAPP) has a great impact on human health. In this thesis, a model system has been taken to study the ultrastructure of the hIAPP aggregates that are present in the fat body tissue surrounding the brain of Drosophila melanogaster. Electron tomography technique on TEM revealed clear crystalline structures in 3D. For the first time, the presence of a 5-fold twinned structure in biology was discovered. An intriguing finding is the filament like interconnection of hIAPP protein granules observed predominantly along the nearest neighbor directions. This suggests the existence of the directional binding forces between two nearest protein granules in addition to dipole-dipole interactions.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2016. 84 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1380
Electron tomography, nanoprecipitate, interfacial structure.
National Category
Physical Sciences
Research subject
Materials Science
urn:nbn:se:uu:diva-284102 (URN)978-91-554-9590-9 (ISBN)
Public defence
2016-06-14, Polhemssalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 13:00 (English)
Available from: 2016-05-23 Created: 2016-04-15 Last updated: 2016-06-15

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Xie, LingLeifer, Klaus
By organisation
Applied Materials Sciences
In the same journal
Journal of Applied Physics
Natural SciencesEngineering and Technology

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: 413 hits
ReferencesLink to record
Permanent link

Direct link