Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • 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
Mechanistic Insights from Functional Group Exchange Surface Passivation: A Combined Theoretical and Experimental Study
KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Theoretical Chemistry and Biology.
KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Theoretical Chemistry and Biology.
KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.ORCID iD: 0000-0002-1591-5815
KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
Show others and affiliations
2019 (English)In: ACS APPLIED ENERGY MATERIALS, ISSN 2574-0962, Vol. 2, no 4, p. 2723-2733Article in journal (Refereed) Published
Abstract [en]

Four different functional groups including amino (-NH2), phosphine (-PH2), hydroxyl (-OH), and thiol (-SH) were combined with POSS (polyhedral oligomeric silsesquioxane) molecules to investigate how functional groups affect the surface passivation of POSS systems. Results from density-functional theory (DFT) calculations indicate that functional group amino (-NH2) with adsorption energy 86 (56) kJ mol(-1) is consistently better than that of thiol (-SH) with adsorption energy 68 (43) kJ mor(-1) for different passivation mechanisms. Theoretical studies on the analogous POSS-OH and POSS-PH2 systems show similar adsorption energies. Two of the systems were also investigated experimentally; aminopropyl isobutyl POSS (POSS-NH2) and mercaptopropyl isobutyl POSS (POSS-SH) were applied as passivation materials for MAPbI(3) (MA = methylammonium) perovskite and (FA)(0.85)(MA)(0.15)Pb(I-3)(0.85)(Br-3)(0)(.15)(FA = formamidinium) perovskite films. The same conclusion was drawn based on the results from contact angle studies, X-ray diffraction (XRD), and the stability of solar cells in ambient atmosphere, indicating the vital importance of choice of functional groups for passivation of the perovskite materials.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC , 2019. Vol. 2, no 4, p. 2723-2733
Keywords [en]
perovskite solar cells, polyhedral oligomeric silsesquioxane (POSS), passivation, DFT calculation, stability
National Category
Inorganic Chemistry
Identifiers
URN: urn:nbn:se:kth:diva-251284DOI: 10.1021/acsaem.9b00050ISI: 000465644600047OAI: oai:DiVA.org:kth-251284DiVA, id: diva2:1316420
Note

QC 20190517

Available from: 2019-05-17 Created: 2019-05-17 Last updated: 2020-02-04Bibliographically approved
In thesis
1. Functional Materials for Perovskite Solar Cells
Open this publication in new window or tab >>Functional Materials for Perovskite Solar Cells
2020 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Energy plays a significant role in our daily lives, but most energy provided by fossil fuels causes serious environmental problems including air pollution, global warming, and ecological damage. In addition, it has been estimated that all of our fossil fuels will run out in 2088 and thus it is highly important to study and apply renewable energy sources. Among all the alternatives, solar energy is clean, sustainable, and abundant. It is estimated that the amount of power from the sun that strikes the earth in 90 minutes is more than the entire world consumes in one year. The perovskite solar cell (PSC) is one of the strongest tools to utilize solar energy because of its high power conversion efficiency and easy fabrication process. However, the lead that is normally used in the perovskite layer is considered harmful to the environment and to human health. Moreover, the low conductivity and hole mobility of the hole-transport material (HTM) Spiro-OMeTAD and the low overall device stability against humidity are all issues that might hinder the further development of PSC technology. This thesis concerns all of these aspects, with a general focus on different functional materials.

The aim of this thesis was to develop environmentally friendly and low-cost functional materials in order to solve existing problems while at the same time revealing insights into carrier transport, molecular doping, and surface passivation.

In Chapter 1 and Chapter 2, the current status of PSCs and the experimental and theoretical methods used in this thesis are presented.

In Chapter 3, the properties of coordination complexes, including molybdenum clusters and polyiodide-linked gold complexes, and their potential application in solar cells as lead-free light absorbers are discussed.

In Chapter 4, the synthesis of four coordination complexes with different metal cores and ligands and their application as HTMs in PSCs is discussed. Their oxidation potential, hole mobility, conductivity, and packing methods are presented.

In Chapter 5, two p-type dopants – Cu(bpcm)2 and (MeO-TPD)TFSI – are introduced for the organic HTM Spiro-OMeTAD. Both of these could significantly increase the conductivity of Spiro-OMeTAD films. In addition, (MeO-TPD)TFSI could work separately without hygroscopic LiTFSI at high doping amounts thus potentially increasing the device’s stability. The structure of oxidized Spiro-OMeTAD on the base of the Spiro(TFSI)2 is also discussed.

In Chapter 6, density functional theory modeling of four different functional groups – including amino (−NH2), phosphine (−PH2), hydroxyl (−OH), and thiol (−SH) groups – in combination with polyhedral oligomeric silsesquioxane is discussed in terms of estimating the adsorption energy with respect to different perovskite surface models. The amino functional group showed the strongest adsorption energy and was further compared with the thiol group in experiments.

Abstract [sv]

Energi spelar en avgörande roll i vårt vardagliga liv. Dessvärre kommer den allra största delen av den energi som tillhandahålls från fossila bränslen, vilka orsakar allvarliga miljöproblem såsom luftföroreningar, global uppvärmning och ekologiska skador. Dessutom finns det uppskattningar som för fram påståenden om att resurserna av fossila bränslen kommer att sina kring 2088, vilket sammantaget understryker behovet av att undersöka och implementera förnybar energi. Bland alternativen återfinns solenergi, vilken ren, hållbar och rikligt tillgänglig. I jämförelse kan det konstateras att den energi som motsvarar ca 1,5 timmes solljus som träffar jordens yta motsvarar en hel årsförbrukning för hela världen. Perovskitsolceller (PSC) utgör en mycket lovande ny teknik för att kunna utnyttja solens energi grundat på deras höga omvandlingseffektivitet tillsammans med enkla tillverkningsprocesser. Dessvärre innehåller perovskitsolcellerna det giftiga grundämnet bly, vilket är skadligt för både miljö och människa. Dessutom är perovskitsolcellerna beroende av omgivande material för att de ska nå höga prestanda, och även dessa är behäftade med problem. Håltransportmaterialet (HTM) Spiro-OMeTAD är förknippat med en inneboende låg ledningsförmåga och känslighet mot fukt. Detta påverkar perovskitsolcellernas stabilitet och utgör ett hinder för vidare utveckling mot en kommersialisering. Den här avhandlingen är fokuserad mot olika funktionella material för perovskitsolceller.

Målet med denna avhandling är att utveckla miljövänliga och billiga funktionella material, vilka kan bidra till att lösa perovskitsolcellernas existerande problem och samtidigt ge insikter om effekterna av laddningstransport, dopning och ytpassivering.

I kapitel 1 och 2 presenteras en statusöversikt för PSC, liksom de experimentella och teoretiska metoder som använts i denna avhandling.

Kapitel 3 ägnas åt implementeringen av nya bly-fria koordinationsföreningar i solceller exemplifierat med två system; molybdenbaserade kluster och polyjodidlänkade guldkomplex. Målet med dessa studier var att identifiera helt nya och bly-fria ljusabsorbenter.

Kapitel 4 ägnas åt studier av fyra nya koordinationsföreningar som HTM till PSC. Dessa omfattar olika metalljoner som koordinationscentra och studerades systematiskt rörande redoxpotentialer, hål-mobilitet, ledningsförmåga samt molekylära packningsmönster.

Kapitel 5 omfattar studier av två nya p-typ dopningsmaterial för organiska hålledare baserade på Cu(bpcm)2 och (MeO-TPD)TFSI. Båda ökar markant ledningsförmågan hos Spiro-OMeTAD. (MeO-TPD)TFSI fungerar dessutom effektivt vid höga koncentrationer utan tillsatser av det hygroskopiska saltet LiTFSI, och detta leder till en tydligt bättre stabilitet hos de resulterande solcellerna. Strukturen hos oxiderad Sprio-OMeTAD resp Spiro(TFSI)2 har analyserats.

I kapiltel 6 undersöks slutligen effekterna av polyhedrala oligomera silsesquioxaner (POSS) med en serie av funktionella sidoarmar terminerade med amin- (−NH2), fosfin (−PH2), hydroxyl (−OH), and tiol (−SH) –grupper. Dessa har undersökts både teoretiskt med hjälp av täthetsfunktionalteori (DFT) för att uppskatta de olika systemens adsorptionsenergier tillsammans med effekter på solceller. POSS-systemen terminerade med amingrupper uppvisade starkast adsorption och tydligast stabiliserande effekter.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2020. p. 80
Series
TRITA-CBH-FOU ; 2020:11
Keywords
perovskite solar cell, photovoltaic device, lead-free light absorbers, hole-transport materials, coordination complexes, p-type dopants, organic salts, surface passivation.
National Category
Chemical Sciences Chemical Sciences
Research subject
Chemistry
Identifiers
urn:nbn:se:kth:diva-267210 (URN)978-91-7873-448-1 (ISBN)
Public defence
2020-02-28, K2, Teknikringen 28, Stockholm, 13:00 (English)
Opponent
Supervisors
Note

QC 2020-02-04

Available from: 2020-02-04 Created: 2020-02-04 Last updated: 2020-02-04Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Authority records BETA

Sadollahkhani, AzarLi, YuanyuanLeandri, ValentinaGardner, James M.Kloo, Lars

Search in DiVA

By author/editor
Zhang, WeiSadollahkhani, AzarLi, YuanyuanLeandri, ValentinaGardner, James M.Kloo, Lars
By organisation
Theoretical Chemistry and BiologyWallenberg Wood Science CenterFibre- and Polymer TechnologyApplied Physical ChemistryCentre of Molecular Devices, CMD
Inorganic Chemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 39 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • 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