Full metadata record
DC FieldValueLanguage
dc.contributorDepartment of Electrical and Electronic Engineeringen_US
dc.contributor.advisorLi, Gang (EEE)en_US
dc.creatorFu, Jiehao-
dc.identifier.urihttps://theses.lib.polyu.edu.hk/handle/200/12912-
dc.languageEnglishen_US
dc.publisherHong Kong Polytechnic Universityen_US
dc.rightsAll rights reserveden_US
dc.titleEngineering photoactive layer towards high-performance organic solar cellsen_US
dcterms.abstractEngineering photoactive layers of organic solar cells (OSCs) by introducing an additive or guest component has been the most widely used method to enhance the performance of OSCs. However, with the evolution of organic light-absorbing materials, traditional additive strategies or guest materials cannot realize the maximum potential of state-of-­the-art OSCs with non-fullerene acceptors (NFAs). Therefore, this thesis proposes three strategies to engineer photoactive layers toward high-performance OSCs.en_US
dcterms.abstractThe first work demonstrates a simple and versatile solid additive, 1,4-diiodobenzene (DIB). Due to the formation of a eutectic phase between the additive and the NFA, a desired microstructure with tighter molecular stacking and more ordered molecular arrangement is achieved. As a result, DIB-treated OSCs display significantly enhanced performance with excellent device stability. Additional advantages of the DIB treatment include toleration of a wide additive concentration range, and versatility in both polymer and small molecule OSCs. The results highlight the importance of additive engineering in high-performance OSCs and demonstrate the significance of supramolecular interactions.en_US
dcterms.abstractThe second work aims to achieve highly efficient OSCs with suppressed non-radiative recombination loss suppression. In this work, we developed a non-monotonic intermediate state manipulation strategy for state-of-the-art OSCs by employing 1,3,5-trichlorobenzene (TCB) as a crystallization regulator, which optimizes the film crystallization process, manipulates the self-organization of bulk-heterojunction in a non-monotonic manner, i.e., first enhancing and then relaxing the molecular aggregation. As a result, the excessive aggregation of non-fullerene acceptors is avoided, and we have achieved efficient organic solar cells with reduced non-radiative recombination loss. In the PM6:BTP-eC9 OSC, our strategy successfully offers a record binary organic solar cell efficiency of 19.31% (18.93% certified) with very low non-radiative recombination loss of 0.190 eV. And lower non-radiative recombination loss of 0.168 eV is further achieved in the PM1:BTP-eC9 OSC (19.10% efficiency), giving great promise to future OOSC research.en_US
dcterms.abstractThe third work is a successful attempt to design and synthesize a NFA guest component for high-performance OSCs. Herein, guided by theoretical calculation, we present a rationally designed NFA, o-BTP-eC9, with much lower synthetic complexity and distinct photoelectric properties than the benchmark BTP-eC9. Moreover, the new NFA o-BTP-eC9 has excellent miscibility, crystallinity, and energy level compatibility with BTP-eC9, which enables a PCE of 19.9% (19.5% certified) in PM6:BTP-C9:o-BTP-eC9 based ternary system with enhanced stability.en_US
dcterms.abstractOur strategies enabled emerging NFA OSCs to achieve continuous performance breakthroughs. Moreover, we deeply investigated the working mechanisms behind the high performance and proposed non-monotonic intermediate state transition induced by additive for the first time. We hope these works can provide insightful guidance for OSC research and inspire more meaningful explorations in this field.en_US
dcterms.extentxxii, 122 pages : color illustrationsen_US
dcterms.isPartOfPolyU Electronic Thesesen_US
dcterms.issued2024en_US
dcterms.educationalLevelPh.D.en_US
dcterms.educationalLevelAll Doctorateen_US
dcterms.LCSHOrganic photovoltaic cellsen_US
dcterms.LCSHSolar cellsen_US
dcterms.LCSHHong Kong Polytechnic University -- Dissertationsen_US
dcterms.accessRightsopen accessen_US

Files in This Item:
File Description SizeFormat 
7352.pdfFor All Users6.96 MBAdobe PDFView/Open


Copyright Undertaking

As a bona fide Library user, I declare that:

  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.

By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

Show simple item record

Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/12912