| 1. |
- Bogachuk, Dmitry, et al.
(författare)
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Perovskite Solar Cells with Carbon-Based Electrodes - Quantification of Losses and Strategies to Overcome Them
- 2022
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Ingår i: Advanced Energy Materials. - : John Wiley & Sons. - 1614-6832 .- 1614-6840. ; 12:10
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Tidskriftsartikel (refereegranskat)abstract
- Carbon-based electrodes represent a promising approach to improve stability and up-scalability of perovskite photovoltaics. The temperature at which these contacts are processed defines the absorber grain size of the perovskite solar cell: in cells with low-temperature carbon-based electrodes (L-CPSCs), layer-by-layer deposition is possible, allowing perovskite crystals to be large (>100 nm), while in cells with high-temperature carbon-based contacts (H-CPSCs), crystals are constrained to 10-20 nm in size. To enhance the power conversion efficiency of these devices, the main loss mechanisms are identified for both systems. Measurements of charge carrier lifetime, quasi-Fermi level splitting (QFLS) and light-intensity-dependent behavior, supported by numerical simulations, clearly demonstrate that H-CPSCs strongly suffer from non-radiative losses in the perovskite absorber, primarily due to numerous grain boundaries. In contrast, large crystals of L-CPSCs provide a long carrier lifetime (1.8 mu s) and exceptionally high QFLS of 1.21 eV for an absorber bandgap of 1.6 eV. These favorable characteristics explain the remarkable open-circuit voltage of over 1.1 V in hole-selective layer-free L-CPSCs. However, the low photon absorption and poor charge transport in these cells limit their potential. Finally, effective strategies are provided to reduce non-radiative losses in H-CPSCs, transport losses in L-CPSCs, and to improve photon management in both cell types.
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| 2. |
- Bogachuk, Dmitry, et al.
(författare)
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Rethinking Electrochemical Deposition of Nickel Oxide for Photovoltaic Applications
- 2024
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Ingår i: Solar RRL. - : John Wiley & Sons. - 2367-198X. ; 8:2
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Tidskriftsartikel (refereegranskat)abstract
- A thin layer of sputtered or wet-processed nickel oxide (NiOx) is often used to fabricate perovskite solar cells (PSCs). Remarkably, NiOx can also be deposited by a recently developed electrochemical method, which is considered promising due to its short processing time, absence of high-vacuum conditions, and ease of manufacturing. Such electrochemically deposited NiOx (eleNiOx) is obtained by applying an electric bias to the front electrode of a PSC or perovskite solar module (PSM). Therefore, the electrode sheet resistance affects the current distribution through it, creating a gradient in the amount of charge provided for the electrochemical reaction. Consequently, this leads to the inhomogeneity in the formed eleNiOx, which has numerous implications on the final photovoltaic performance of PSMs. In this work, the interdependencies between the electrode sheet resistance, current distribution, eleNiOx thickness gradient, and the caused power losses of large area PSMs are discussed. By coupling the experimental findings with our numerical simulations, it is found that heterogeneity in surface potential of even small-sized modules can lead to severe differences in local eleNiOx thickness and photovoltaic performance. Therefore the potential drop across the front electrode is an inherent problem of this deposition method and potential approaches are proposed to minimize it. The synergy between several numerical simulation methods and the experimental work provides an additional critical insight into the electrochemical deposition process of nickel oxide and how important it is for the performance and stability of the large-area perovskite photovoltaic modules. It is believed that the conclusions drawn from this study are universally applicable to other electrochemically deposited layers as well.image (c) 2023 WILEY-VCH GmbH
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| 3. |
- Minkevich, Natalya I., et al.
(författare)
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Abnormal pigment epithelium-derived factor processing in progressive myopia
- 2016
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Ingår i: Experimental Eye Research. - : Elsevier BV. - 0014-4835 .- 1096-0007. ; 152, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Pigment Epithelium-Derived Factor (PEDF) is a secreted glycoprotein belonging to the family of non inhibitory serpins. It is known, that in cases of complicated myopia, the content of PEDF in aqueous humor of the anterior chamber is significantly reduced. Here we examined a bulk of Tenon's capsule samples obtained from various groups of myopes, to examine PEDF processing in progressive myopia. We have analyzed the distribution of full length PEDF50 and its truncated form PEDF45 in the soluble and insoluble fractions extracted from Tenon's capsule of myopic and control (non-myopic) patients using SDS-polyacrylamide gel electrophoresis, as well as monitored the proteolytic degradation of PEDF ex vivo by enzyme-linked immunosorbent assay. These results were complemented by PEDF mRNA analysis in correspondent tissues by using qPCR and immunohistochemistry analysis of PEDF distribution in normal and myopic specimens. We found that in the Tenon's capsule of patients suffering from a high myopia the level of "soluble" 45 kDa PEDF reduced by 2-fold, while the content of "insoluble" 50 kDa form of PEDF was increased by 4-fold compared to controls. Excessive amount of PEDF50 in myopic specimens have been shown to correlate with the abrogated PEDF processing rather than with an increase of its expression. Moreover, immunohistochemical staining of the myopic Tenon's capsule tissue sections revealed the halo of deposited PEDF50 in the fibroblast extracellular space. These findings suggest that in myopia limited proteolysis of PEDF is altered or abrogated. Accumulation of full-length PEDF insoluble aggregates in the fibroblast intercellular space may affect cell survival and consequently causes the destructive changes in the extracellular matrix of the eye connective tissues. As a result, the abrogation of full-length PEDF normal processing can be an important mechanism leading to biomechanical destabilization of the scleral capsule and myopia progression.
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| 4. |
- Suo, Jiajia, et al.
(författare)
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Multifunctional sulfonium-based treatment for perovskite solar cells with less than 1% efficiency loss over 4,500-h operational stability tests
- 2024
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Ingår i: Nature Energy. - : NATURE PORTFOLIO. - 2058-7546.
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Tidskriftsartikel (refereegranskat)abstract
- The stabilization of grain boundaries and surfaces of the perovskite layer is critical to extend the durability of perovskite solar cells. Here we introduced a sulfonium-based molecule, dimethylphenethylsulfonium iodide (DMPESI), for the post-deposition treatment of formamidinium lead iodide perovskite films. The treated films show improved stability upon light soaking and remains in the black alpha phase after two years ageing under ambient condition without encapsulation. The DMPESI-treated perovskite solar cells show less than 1% performance loss after more than 4,500 h at maximum power point tracking, yielding a theoretical T80 of over nine years under continuous 1-sun illumination. The solar cells also display less than 5% power conversion efficiency drops under various ageing conditions, including 100 thermal cycles between 25 degrees C and 85 degrees C and an 1,050-h damp heat test. Suo et al. show that sulfonium-based molecules afford formamidinium lead iodide perovskites protection against environmental stress factors, improved phase stability and solar cells retaining efficiency over 4,500-h operational stability tests.
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| 5. |
- Wagner, Lukas, et al.
(författare)
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The resource demands of multi-terawatt-scale perovskite tandem photovoltaics
- 2024
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Ingår i: Joule. - : Elsevier. - 2542-4351. ; 8:4, s. 1142-1160
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Tidskriftsartikel (refereegranskat)abstract
- Photovoltaics (PV) and wind are the most important energy -conversion technologies for cost-efficient climate change mitigation. To reach international climate goals, the annual PV module production must be expanded to multi-terawatt (TW) scale. Economic and resource restraints demand the implementation of cost-efficient multi -junction technologies, for which perovskite-based tandem technologies are highly promising. In this work, the resource demand of the emerging perovskite PV technology is investigated, considering two factors of supply criticality, namely, mining capacity for minerals and the production capacity for synthetic materials. Overall, the expansion of perovskite PV to a multi-TW scale may not be limited by material supply if certain materials, especially indium, can be replaced. Moreover, organic charge -transport materials face currently unresolved scalability challenges. This study demonstrates that, besides the improvement of efficiency and stability, perovskite PV research and development also need to be guided by sustainable materials choices and design -for -recycling considerations.
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| 6. |
- Yang, Bowen, et al.
(författare)
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A universal ligand for lead coordination and tailored crystal growth in perovskite solar cells
- 2024
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Ingår i: Energy & Environmental Science. - : Royal Society of Chemistry. - 1754-5692 .- 1754-5706. ; 17:4, s. 1549-1558
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Tidskriftsartikel (refereegranskat)abstract
- Chemical environment and precursor-coordinating molecular interactions within a perovskite precursor solution can lead to important implications in structural defects and crystallization kinetics of a perovskite film. Thus, the opto-electronic quality of such films can be boosted by carefully fine-tuning the coordination chemistry of perovskite precursors via controllable introduction of additives, capable of forming intermediate complexes. In this work, we employed a new type of ligand, namely 1-phenylguanidine (PGua), which coordinates strongly with the PbI2 complexes in the perovskite precursor, forming new intermediate species. These strong interactions effectively retard the perovskite crystallization process and form homogeneous films with enlarged grain sizes and reduced density of defects. In combination with an interfacial treatment, the resulted champion devices exhibit a 24.6% efficiency with outstanding operational stability. Unprecedently, PGua can be applied in various PSCs with different perovskite compositions and even in both configurations: n-i-p and p-i-n, highlighting the universality of this ligand.
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| 7. |
- Yang, Bowen, et al.
(författare)
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Interfacial Passivation Engineering of Perovskite Solar Cells with Fill Factor over 82% and Outstanding Operational Stability on n-i-p Architecture
- 2021
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Ingår i: ACS Energy Letters. - : American Chemical Society (ACS). - 2380-8195. ; 6:11, s. 3916-3923
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Tidskriftsartikel (refereegranskat)abstract
- Tremendous efforts have been dedicated toward minimizing the open-circuit voltage deficits on perovskite solar cells (PSCs), and the fill factors are still relatively low. This hinders their further application in large scalable modules. Herein, we employ a newly designed ammonium salt, cyclohexylethylammonium iodide (CEAI), for interfacial engineering between the perovskite and hole-transporting layer (HTL), which enhanced the fill factor to 82.6% and consequent PCE of 23.57% on the target device. This can be associated with a reduction of the trap-assisted recombination rate at the 3D perovskite surface, via formation of a 2D perovskite interlayer. Remarkably, the property of the 2D perovskite interlayer along with the cyclohexylethyl group introduced by CEAI treatment also determines a pronounced enhancement in the surface hydrophobicity, leading to an outstanding stability of over 96% remaining efficiency of the passivated devices under maximum power point tracking with one sun illumination under N-2 atmosphere at room temperature after 1500 h.
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| 8. |
- Yang, Bowen, et al.
(författare)
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Strain effects on halide perovskite solar cells
- 2022
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Ingår i: Chemical Society Reviews. - : Royal Society of Medicine Press. - 0306-0012 .- 1460-4744. ; 51:17, s. 7509-7530
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Forskningsöversikt (refereegranskat)abstract
- Halide perovskite solar cells (PSCs) have achieved power conversion efficiencies (PCEs) approaching 26%, however, the stability issue hinders their commercialization. Due to the soft ionic nature of perovskite materials, the strain effect on perovskite films has been recently recognized as one of the key factors that affects their opto-electronic properties and the device stability. Herein, we summarized the origins of strain, characterization techniques, and implications of strain on both perovskite film and solar cells as well as various strategies to control the strain. Finally, we proposed effective strategies for future strain engineering. We believe this comprehensive review could further facilitate researchers with a deeper understanding of strain effect and enhance the research activity in engineering the strain to further improve performance and especially the device stability toward commercialization.
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