| 1. |
- Bai, Yang, et al.
(author)
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Geometry design of tethered small-molecule acceptor enables highly stable and efficient polymer solar cells
- 2023
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In: Nature Communications. - : NATURE PORTFOLIO. - 2041-1723. ; 14:1
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Journal article (peer-reviewed)abstract
- With the power conversion efficiency of binary polymer solar cells dramatically improved, the thermal stability of the small-molecule acceptors raised the main concerns on the device operating stability. Here, to address this issue, thiophene-dicarboxylate spacer tethered small-molecule acceptors are designed, and their molecular geometries are further regulated via the thiophene-core isomerism engineering, affording dimeric TDY-alpha with a 2, 5-substitution and TDY-beta with 3, 4-substitution on the core. It shows that TDY-alpha processes a higher glass transition temperature, better crystallinity relative to its individual small-molecule acceptor segment and isomeric counterpart of TDY-beta, and amore stablemorphology with the polymer donor. As a result, the TDY-alpha based device delivers a higher device efficiency of 18.1%, and most important, achieves an extrapolated lifetime of about 35000 hours that retaining 80% of their initial efficiency. Our result suggests that with proper geometry design, the tethered small-molecule acceptors can achieve both high device efficiency and operating stability.
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| 2. |
- Chang, Qingyan, et al.
(author)
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Precursor engineering enables high-performance all-inorganic CsPbIBr2 perovskite solar cells with a record efficiency approaching 13%
- 2024
-
In: Journal of Energy Chemistry. - : Elsevier BV. - 2095-4956 .- 2096-885X. ; 90, s. 16-22
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Journal article (peer-reviewed)abstract
- All-inorganic CsPbIBr2 perovskite has attracted widespread attention in photovoltaic and other optoelectronic devices because of its superior thermal stability. However, the deposition of high-quality solution-processed CsPbIBr2 perovskite films with large thicknesses remains challenging. Here, we develop a triple-component precursor (TCP) by employing lead bromide, lead iodide, and cesium bromide, to replace the most commonly used double-component precursor (DCP) consisting of lead bromide and cesium iodide. Remarkably, the TCP system significantly increases the solution concentration to 1.3 M, leading to a larger film thickness (∼390 nm) and enhanced light absorption. The resultant CsPbIBr2 films were evaluated in planar n-i-p structured solar cells, which exhibit a considerably higher optimal photocurrent density of 11.50 mA cm−2 in comparison to that of DCP-based devices (10.69 mA cm−2). By adopting an organic surface passivator, the maximum device efficiency using TCP is further boosted to a record efficiency of 12.8% for CsPbIBr2 perovskite solar cells.
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| 3. |
- Liu, Qi, et al.
(author)
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Surface passivation and hole extraction : Bifunctional interfacial engineering toward high-performance all-inorganic CsPbIBr2 perovskite solar cells with efficiency exceeding 12%
- 2022
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In: Journal of Energy Challenges and Mechanics. - : Elsevier BV. - 2056-9386. ; 74, s. 387-393
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Journal article (peer-reviewed)abstract
- All-inorganic CsPbIBr2 perovskite solar cells (PSCs) have attracted considerable research attention in recent years due to their excellent thermal stability. However, their power conversion efficiencies (PCEs) are relatively low and still far below the theoretical limit. Here, we report the use of an organic dye molecule (namely VG1-C8) as a bifunctional interlayer between perovskite and the hole-transport layer in CsPbIBr2 PSCs. Combined experimental and theoretical calculation results disclose that the mul-tiple Lewis base sites in VG1-C8 can effectively passivate the trap states on the perovskite films. Meanwhile, the p-conjugated dye molecule significantly accelerates the hole extraction from the per-ovskite absorber as evidenced by the photoluminescence analysis. Consequently, the VG1-C8 treatment simultaneously boosts the photovoltage and photocurrent density values from 1.26 V and 10.80 mA cm -2 to 1.31 V and 12.44 mA cm -2, respectively. This leads to a significant enhancement of PCE from 9.20% to 12.10% under one sun irradiation (AM 1.5G). To our knowledge, this is the record efficiency reported so far for CsPbIBr2 PSCs. Thus, the present work demonstrates an effective interfacial passivation strategy for the development of highly efficient PSCs.
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