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

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • 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
Baseline model of graded-absorber Cu(In,Ga)Se2 solar cells applied to cells with Zn1−xMgxO buffer layers
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics. (Solar Cell Group)
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics. (Solar Cell Group)
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics. (Solar Cell Group)
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics. (Solar Cell Group)
2011 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 519, no 21, 7476-7480 p.Article in journal (Refereed) Published
Abstract [en]

A baseline parameter set for electrical modelling of Cu(In,Ga)Se2 solar cells with compositionally graded absorber and CdS buffer layer is established. The cases with and without Fermi level pinning as well as withand without a surface defect layer are considered. Simulations with a defect layer are observed to give the best correspondence to measurements. Zn1−xMgxO buffer layers are introduced and initial modelling of the lightsoaking behaviour is performed. Simulation results are compared with experimental data.

Place, publisher, year, edition, pages
Elsevier , 2011. Vol. 519, no 21, 7476-7480 p.
Keyword [en]
Electrical modelling, CIGS solar cells, Buffer layers, Graded absorber, Light-soaking, Metastabilities
National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Electronics
Identifiers
URN: urn:nbn:se:uu:diva-157808DOI: 10.1016/j.tsf.2010.12.141ISI: 000295347700082OAI: oai:DiVA.org:uu-157808DiVA: diva2:436314
Available from: 2011-08-23 Created: 2011-08-23 Last updated: 2017-12-08Bibliographically approved
In thesis
1. Modelling Band Gap Gradients and Cd-free Buffer Layers in Cu(In,Ga)Se2 Solar Cells
Open this publication in new window or tab >>Modelling Band Gap Gradients and Cd-free Buffer Layers in Cu(In,Ga)Se2 Solar Cells
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

A deeper understanding of Cu(In,Ga)Se2 (CIGS) solar cells is important for the further improvement of these devices. This thesis is focused on the use of electrical modelling as a tool for pursuing this aim. Finished devices and individual layers are characterized and the acquired data are used as input in the simulations. Band gap gradients are accounted for when modelling the devices. The thesis is divided into two main parts. One part that treats the influence of cadmium free buffer layers, mainly atomic layer deposited (Zn,Mg)O, on devices and another part in which the result of CIGS absorber layer modifications is studied. Recombination analysis indicates that interface recombination is limitting the open circuit voltage (Voc) in cells with ZnO buffer layers. This recombination path becomes less important when magnesium is introduced into the ZnO giving a positive conduction band offset (CBO) towards the CIGS absorber layer. Light induced persistent photoconductivity (PPC) is demonstrated in (Zn,Mg)O thin films. Device modelling shows that the measured PPC, coupled with a high density of acceptors in the buffer-absorber interface region, can explain light induced metastable efficiency improvement in CIGS solar cells with (Zn,Mg)O buffer layers. It is shown that a thin indium rich layer closest to the buffer does not give any significant impact on the performance of devices dominated by recombination in the CIGS layer. In our cells with CdS buffer the diffusion length in the CIGS layer is the main limitting factor. A thinner CIGS layer improves Voc by reducing recombination. However, for thin enough absorber layers Voc deteriorates due to recombination at the back contact. Interface recombination is a problem in thin devices with Zn(O,S) buffer layers. This recombination path is overshadowed in cells of standard thickness by recombination in the CIGS bulk. Thin cells with Zn(O,S) buffer layers have a higher efficiency than CdS cells with the same absorber thickness.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2012. 70 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 900
Keyword
CIGS, Thin film solar cells, Electrical modelling, Alternative buffer layers, Gallium gradients, Simulations, Electrical characterization, Metastabilities, Light-soaking, Hall measurements, Persistent photoconductivity
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering Materials Engineering Physical Sciences
Research subject
Engineering Science with specialization in Electronics
Identifiers
urn:nbn:se:uu:diva-168618 (URN)978-91-554-8280-0 (ISBN)
Public defence
2012-03-30, Polhemssalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 13:15 (English)
Opponent
Supervisors
Available from: 2012-03-09 Created: 2012-02-13 Last updated: 2013-04-08Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Authority records BETA

Pettersson, JonasPlatzer-Björkman, CharlotteZimmermann, UweEdoff, Marika

Search in DiVA

By author/editor
Pettersson, JonasPlatzer-Björkman, CharlotteZimmermann, UweEdoff, Marika
By organisation
Solid State Electronics
In the same journal
Thin Solid Films
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 912 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • 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