uu.seUppsala universitets publikationer
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Geometrical and energetical structural changes in organic dyes for dye-sensitized solar cells probed with photoelectron spectroscopy and DFT
Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Fysikalisk kemi.
Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Fysikalisk kemi.
Visa övriga samt affilieringar
2016 (Engelska)Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 18, nr 1, s. 252-260Artikel i tidskrift (Övrigt vetenskapligt) Published
Abstract [en]

The effects of alkoxy chain length in triarylamine based donor acceptor organic dyes are investigated with respect to the electronic and molecular surface structures on the performance of solar cells and the electron lifetime. The dyes were investigated when adsorbed on TiO2 in a configuration that can be used for dye sensitized solar cells (DSCs). Specifically, the two dyes D35 and D45 were compared using photoelectron spectroscopy (PES) and density functional theory (DFT) calculations. The differences in solar cell characteristics when longer alkoxy chains are introduced in the dye donor unit are attributed to geometrical changes in dye packing while only minor differences were observed in the electronic structure. A higher dye load was observed for D45 on TiO2. However, D35 based solar cells result in higher photocurrent although the dye load is lower. This is explained by different geometrical structures of the dyes on the surface.

Ort, förlag, år, upplaga, sidor
2016. Vol. 18, nr 1, s. 252-260
Nationell ämneskategori
Fysikalisk kemi
Identifikatorer
URN: urn:nbn:se:uu:diva-230853DOI: 10.1039/c5cp04589dISI: 000368755500027OAI: oai:DiVA.org:uu-230853DiVA, id: diva2:742135
Forskningsfinansiär
VetenskapsrådetCarl Tryggers stiftelse för vetenskaplig forskning EnergimyndighetenStandUpTillgänglig från: 2014-08-31 Skapad: 2014-08-31 Senast uppdaterad: 2017-12-05Bibliografiskt granskad
Ingår i avhandling
1. Interfaces in Dye-Sensitized Solar Cells Studied with Photoelectron Spectroscopy at Elevated Pressures
Öppna denna publikation i ny flik eller fönster >>Interfaces in Dye-Sensitized Solar Cells Studied with Photoelectron Spectroscopy at Elevated Pressures
2014 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

With an increasing demand for renewable energy sources, research efforts on different solar cell technologies are increasing rapidly. The dye-sensitized solar cell (DSC) is one such technology, taking advantage of light absorption in dye molecules. The liquid based DSC contains several interesting and important interfaces, crucial for the understanding and development of the solar cell performance. Examples of such interfaces include dye-semiconductor, electrode-electrolyte and solute-solvent interfaces. Ultimately, complete interfaces with all these components included are of particular interest. One major challenge is to understand the key functions of these systems at an atomic level and one way to achieve this is to use an element specific and surface sensitive tool, such as photoelectron spectroscopy (PES). This thesis describes the use and development of PES for studying interfaces in the DSC.

The materials part of the thesis focuses on interfaces in DSCs studied with PES and the methodology development parts focus on methods to use PES for investigations of solvated heterogeneous interfaces of interest for photoelectrochemical systems such as the DSC. More specifically, beginning with standard vacuum techniques, dye molecules bound to a semiconductor surface have been studied in terms of energy level alignment, surface coverage and binding configuration. To increase the understanding of solvation phenomena present in the liquid DSC, liquid jet experiments have been performed in close combination with theoretical quantum calculations. As a step towards an in-situ method to measure a complete, functioning (in operando) solar cell, methodology development and measurements performed with higher sample pressures are described using new high pressure X-ray photoelectron spectroscopy techniques (HPXPS).

Ort, förlag, år, upplaga, sidor
Uppsala: Acta Universitatis Upsaliensis, 2014. s. 75
Serie
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1173
Nyckelord
Dye-sensitized solar cells, interfaces, solvation, photoelectron spectroscopy, HPXPS, HP-HAXPES, liquid jet
Nationell ämneskategori
Fysikalisk kemi
Forskningsämne
Kemi med inriktning mot fysikalisk kemi
Identifikatorer
urn:nbn:se:uu:diva-230855 (URN)978-91-554-9022-5 (ISBN)
Disputation
2014-10-17, Häggsalen, Ångström laboratory, Uppsala, 10:15 (Engelska)
Opponent
Handledare
Tillgänglig från: 2014-09-25 Skapad: 2014-08-31 Senast uppdaterad: 2015-01-23
2. Towards Mixed Molecular Layers for Dye-Sensitized Solar Cells: A Photoelectron Spectroscopy Study
Öppna denna publikation i ny flik eller fönster >>Towards Mixed Molecular Layers for Dye-Sensitized Solar Cells: A Photoelectron Spectroscopy Study
2016 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

The increasing demand for renewable energy has led to substantial research on different solar cell technologies. The dye-sensitized solar cell (DSC) is a technology utilizing dye molecules for light absorption. Dye molecules are adsorbed to a mesoporous semiconductor surface and after light absorption in the dye, charge separation occurs at this interface. Traditionally, DSCs have used layers of single dye species, but in recent efforts to enhance power conversion efficiency, more complex molecular layers have been designed to increase the light absorption. For example, the most efficient DSCs use a combination of two dye molecules, and such dye co-adsorption is studied in this thesis.

A key to highly efficient DSCs is to understand the dye/semiconductor interface from a molecular perspective. One way of gaining this understanding is by using an element specific, surface sensitive technique, such as photoelectron spectroscopy (PES).

In this thesis, PES is used to understand new complex dye/semiconductor interfaces. Dyes adsorbed to semiconductor surfaces are analyzed using PES in terms of geometric and electronic surface structure.  The investigations ultimately target the effects of co-adsorbing dyes with other dyes or co-adsorbents.

PES shows that Ru dyes can adsorb in mixed configurations to TiO2. Co-adsorption with an organic dye affects the configuration of the Ru dyes. As a consequence, shifts in energy level alignment and increased dye coverage are observed. The dyes are affected at a molecular level in ways beneficial for solar cell performance. This is called collaborative sensitization and is also observed in todays most efficient DSC.

Dye molecules are generally sensitive to high temperatures and the substantial decrease in power conversion efficiency after heat-treatment can be understood using PES. Furthermore, comparing two mesoscopic TiO2 morphologies used in DSCs show differences in trap state density in the band gap, explaining the photovoltage difference in DSCs comprising these morphologies. Using mixed molecular layers on NiO results in significant improvements of p-type DSC power conversion efficiency. PES shows that changed adsorption configuration contribute to this effect.

This thesis shows that PES studies can be used to obtain insight into functional properties of complex DSC interfaces at a molecular level.

Ort, förlag, år, upplaga, sidor
Uppsala: Acta Universitatis Upsaliensis, 2016. s. 81
Serie
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1409
Nyckelord
dye-sensitized solar cell, DSC, mesoscopic solar cell, photoelectron spectroscopy, PES, XPS, interface, TiO2, NiO, co-adsorption, co-adsorbent, collaborative sensitization, mixed molecular layers
Nationell ämneskategori
Den kondenserade materiens fysik
Forskningsämne
Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik
Identifikatorer
urn:nbn:se:uu:diva-301164 (URN)978-91-554-9664-7 (ISBN)
Disputation
2016-10-06, Häggsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 10:15 (Engelska)
Opponent
Handledare
Tillgänglig från: 2016-09-14 Skapad: 2016-08-18 Senast uppdaterad: 2016-09-22

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Förlagets fulltext

Personposter BETA

Eriksson K., SusannaEllis, HannaOscarsson, JohanLindblad, RebeckaEriksson, Anna I. K.Johansson, ErikBoschloo, GerritHagfeldt, AndersRensmo, Håkan

Sök vidare i DiVA

Av författaren/redaktören
Eriksson K., SusannaEllis, HannaOscarsson, JohanLindblad, RebeckaEriksson, Anna I. K.Johansson, ErikBoschloo, GerritHagfeldt, AndersRensmo, Håkan
Av organisationen
Fysikalisk kemiMolekyl- och kondenserade materiens fysik
I samma tidskrift
Physical Chemistry, Chemical Physics - PCCP
Fysikalisk kemi

Sök vidare utanför DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 1092 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf