Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor | Department of Electrical and Electronic Engineering | en_US |
| dc.contributor.advisor | Li, Gang (EEE) | en_US |
| dc.creator | Li, Dongyang | - |
| dc.identifier.uri | https://theses.lib.polyu.edu.hk/handle/200/13961 | - |
| dc.language | English | en_US |
| dc.publisher | Hong Kong Polytechnic University | en_US |
| dc.rights | All rights reserved | en_US |
| dc.title | Interface engineering towards highly efficient inverted perovskite solar cells | en_US |
| dcterms.abstract | The rapid advancements in perovskite solar cells (PSCs) technology have brought efficiencies comparable to silicon-based solar cells within a relatively short period. Despite these achievements, challenges such as stability, processibility and manufacturability issues hinder the developments of high efficiency PSCs. In addition, non-radiative recombination loss persists due to imperfect semiconducting properties and interfaces such as various defects. | en_US |
| dcterms.abstract | This PhD research focus on interfacial engineering in PSCs, and three major strategies are investigated: surface passivation at the top perovskite surface, buried interface optimization, and molecular design and synthesis of self-assembled monolayers (SAMs). | en_US |
| dcterms.abstract | Chapter 4 presents a strategy focused on enhancing the surface properties of inverted p-i-n PSCs (IPSCs) by incorporating an organic semiconductor - polymerized small molecular acceptor (PSMA) at the top surface of perovskite. This surface regulation approach led to improved grain orientation and reduced defect density, significantly boosting electron transport and overall device performance. The results demonstrated a marked power conversion efficiency (PCE) of 23.57%, with a fill factor (FF) of 84%. Stability tests showed promising results, with PSMA-treated devices retaining approximately 80% of their initial PCE after 1000 hours of continuous illumination under maximum power point (MPP) tracking. This chapter underscores the role of targeted surface passivation in achieving high efficiency and stability in IPSCs. | en_US |
| dcterms.abstract | Chapter 5 explores a co-adsorbed (CA) approach for buried interface engineering in IPSCs. By employing 2-chloro-5-(trifluoromethyl)isonicotinic acid (PyCA-3F) between the 2PACz SAM and perovskite/organic layers, interfacial energy losses were minimized. This strategy reduced aggregation, enhanced surface smoothness, and improved the work function (WF) of the SAM, creating a well-aligned heterointerface. The resulting devices exhibited enhanced crystallinity, minimized trap states, and efficient charge transfer, achieving a certified PCE of 24.68%. Furthermore, the CA strategy was also effective in organic solar cells (OSCs), resulting in a PCE of 19.51%. Both device types maintained over 80% of their initial efficiency after prolonged operation, highlighting the effectiveness of this method in enhancing both performance and longevity. | en_US |
| dcterms.abstract | Chapter 6 investigates the design and synthesis of novel self-assembled SAM in IPSCs. Two SAMs, PABDCB and MeO-PABDCB, featuring rigid phenylene linkers, were developed to construct densely packed, organized hole transport layers (HTLs). By replacing flexible carbon chains with rigid phenylene linkers, we achieve highly dense and ordered SAM coverage and preferable tridentate binding on ITO substrates. The methoxy-terminated SAM MeO-PABDCB further enhances interfacial dipole moments and passivates perovskite defects via Lewis basicity, thereby reducing trap-assisted recombination. Our combined experimental and theoretical analyses reveal that rigid phenylene linkers minimize structural disorganization and improve π−π stacking, while methoxy termini align energy levels and stabilize interfaces. This SAM design yields enhancement in IPSCs with a power conversion efficiency of 26.25% and a fill factor of 86.4%, alongside exceptional operational and robust thermal cycle stability. Our work establishes a molecular engineering strategy that leverages rigidity through rigid linkers and tailored termini to advance SAM-based photovoltaics toward commercial viability. | en_US |
| dcterms.abstract | These findings collectively underscore the importance of targeted interface engineering in enhancing the efficiency and durability of IPSCs, moving them closer to commercial applications in the near future. | en_US |
| dcterms.extent | xxv, 178 pages : color illustrations | en_US |
| dcterms.isPartOf | PolyU Electronic Theses | en_US |
| dcterms.issued | 2025 | en_US |
| dcterms.educationalLevel | Ph.D. | en_US |
| dcterms.educationalLevel | All Doctorate | en_US |
| dcterms.accessRights | open access | en_US |
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