| 1. |
- Kim, Minjin, et al.
(författare)
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Conformal quantum dot-SnO2 layers as electron transporters for efficient perovskite solar cells
- 2022
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 375:6578, s. 302-306
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Tidskriftsartikel (refereegranskat)abstract
- Improvements to perovskite solar cells (PSCs) have focused on increasing their power conversion efficiency (PCE) and operational stability and maintaining high performance upon scale-up to module sizes. We report that replacing the commonly used mesoporous-titanium dioxide electron transport layer (ETL) with a thin layer of polyacrylic acid-stabilized tin(IV) oxide quantum dots (paa-QD-SnO2) on the compact-titanium dioxide enhanced light capture and largely suppressed nonradiative recombination at the ETL-perovskite interface. The use of paa-QD-SnO2 as electron-selective contact enabled PSCs (0.08 square centimeters) with a PCE of 25.7% (certified 25.4%) and high operational stability and facilitated the scale-up of the PSCs to larger areas. PCEs of 23.3, 21.7, and 20.6% were achieved for PSCs with active areas of 1, 20, and 64 square centimeters, respectively.
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| 2. |
- Jeong, Jaeki, et al.
(författare)
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Pseudo-halide anion engineering for α-FAPbI3 perovskite solar cells
- 2021
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Ingår i: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 592:7854, s. 381-385
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Tidskriftsartikel (refereegranskat)abstract
- Metal halide perovskites of the general formula ABX(3)-where A is a monovalent cation such as caesium, methylammonium or formamidinium; B is divalent lead, tin or germanium; and X is a halide anion-have shown great potential as light harvesters for thin-film photovoltaics(1-5). Among a large number of compositions investigated, the cubic a-phase of formamidinium lead triiodide (FAPbI(3)) hasemerged as the most promising semiconductor for highly efficient and stable perovskite solar cells(6-9), and maximizing the performance of this material in such devices is of vital importance for the perovskite researchcommunity. Here we introduce an anion engineering concept that uses the pseudo-halide anion formate (HCOO-) to suppress anion-vacancy defects that are present at grain boundaries and at the surface of the perovskite films and to augment the crystallinity of the films. Theresulting solar cell devices attain a power conversion efficiency of 25.6 per cent (certified 25.2 per cent), have long-term operational stability (450 hours) and show intense electroluminescence with external quantum efficiencies of more than 10 per cent. Our findings provide a direct route to eliminate the most abundant and deleterious lattice defects present in metal halide perovskites, providing a facile access to solution-processable films with improved optoelectronic performance.
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| 3. |
- Lee, Dong Geon, et al.
(författare)
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High Efficiency Perovskite Solar Cells Exceeding 22% via a Photo-Assisted Two-Step Sequential Deposition
- 2021
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Ingår i: Advanced Functional Materials. - : John Wiley & Sons. - 1616-301X .- 1616-3028. ; 31:9
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Tidskriftsartikel (refereegranskat)abstract
- One of the most effective methods to achieve high-performance perovskite solar cells (PSCs) is to employ additives as crystallization agents or to passivate defects. Tri-iodide ion has been known as an efficient additive to improve the crystallinity, grain size, and morphology of perovskite films. However, the generation and control of this tri-iodide ion are challenging. Herein, an efficient method to produce tri-iodide ion in a precursor solution using a photoassisted process for application in PSCs is developed. Results suggest that the tri-iodide ion can be synthesized rapidly when formamidinium iodide (FAI) dissolved isopropyl alcohol (IPA) solution is exposed to LED light. Specifically, the photoassisted FAI-IPA solution facilitates the formation of fine perovskite films with high crystallinity, large grain size, and low trap density, thereby improving the device performance up to 22%. This study demonstrates that the photoassisted process in FAI dissolved IPA solution can be an alternative strategy to fabricate highly efficient PSCs with significantly reduced processing times.
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| 4. |
- Jeon, Jae Bum, et al.
(författare)
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Photo-annealed amorphous titanium oxide for perovskite solar cells
- 2019
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Ingår i: Nanoscale. - : Royal Society of Chemistry. - 2040-3364 .- 2040-3372. ; 11:41, s. 19488-19496
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Tidskriftsartikel (refereegranskat)abstract
- Electron selective layers are important to the efficiency, stability and hysteresis of perovskite solar cells. Photo-annealing is a low-cost, roll-to-roll-compatible process that can be applied to the post-treatment fabrication of sol-gel based metal oxide layers. Here, we fabricate an amorphous titanium oxide electron selective layer at a low temperature in a dry atmosphere using a UV light annealing system and compare it with a thermal annealing process. Active oxygen species are created by using UV light to promote hydrolysis and condense the TiO2 precursor, which removes organic ligands effectively. The photo-annealed TiO2-based perovskite solar cell has a power conversion efficiency of 19.37% without hysteresis.
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| 5. |
- Kim, Byeong Jo, et al.
(författare)
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High-Efficiency Flexible Perovskite Solar Cells Enabled by an Ultrafast Room-Temperature Reactive Ion Etching Process
- 2020
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 12:6, s. 7125-7134
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Tidskriftsartikel (refereegranskat)abstract
- Perovskite solar cells (PSCs), which have surprisingly emerged in recent years, are now aiming at commercialization. Rapid, low-temperature, and continuous fabrication processes that can produce high-efficiency PSCs with a reduced fabrication cost and shortened energy payback time are important challenges on the way to commercialization. Herein, we report a reactive ion etching (RIE) method, which is an ultrafast room-temperature technique, to fabricate mesoporous TiO2 (mp-TiO2) as an electron transport layer for high-efficiency PSCs. Replacing the conventional high-temperature annealing process by RIE reduces the total processing time for fabricating 20 PSCs by 40%. Additionally, the RIE-processed mp-TiO2 exhibits enhanced electron extraction, whereupon the optimized RIE-mp-TiO2-based PSC exhibits a power conversion efficiency (PCE) of 19.60% without J–V hysteresis, when the devices were optimized with a TiCl4 surface treatment process. Finally, a flexible PSC employing RIE-mp-TiO2 is demonstrated with 17.29% PCE. Considering that the RIE process has been actively used in the semiconductor industry, including for the fabrication of silicon photovoltaic modules, the process developed in this work could be easily applied toward faster, simpler, and cheaper manufacturing of PSC modules.
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| 6. |
- Lee, Dong Geon, et al.
(författare)
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Effect of Metal Electrodes on Aging-Induced Performance Recovery in Perovskite Solar Cells
- 2019
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Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 11:51, s. 48497-48504
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Tidskriftsartikel (refereegranskat)abstract
- For commercialization of perovskite solar cells (PSCs), it is important to substitute the alternative electrode for Au to decrease the unit cost. From the early stage, Ag exhibits a potential to be a good counter electrode in PSCs; however, there is an abnormal s-shaped J-V curve with the Ag electrode, and it is recovered as time passes. The perception of the aging-induced recovery process and refutation of the raised stability issues are required for commercial application of Ag electrodes. Herein, we compared the aging effect of PSCs with Ag and Au electrodes and found that only devices with Ag electrodes have a dramatical aging-induced recovery process. We observed the change of photoelectronic properties only in the devices with Ag electrodes as time passes, which mainly contributes to recovery of the s-shaped J-V curve. We verified the work function change of an aged Ag electrode and its mechanism by photoelectron spectroscopy analysis. By comparing the light stability under 1 sun intensity illumination, we can assure the practical stability of Ag electrodes in case of being encapsulated. This work suggests the profound understanding of the aging-induced recovery process of PSCs and the possibility of commercial application of Ag electrodes.
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| 7. |
- Park, So Yeon, et al.
(författare)
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Sustainable lead management in halide perovskite solar cells
- 2020
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Ingår i: Nature Sustainability. - : NATURE RESEARCH. - 2398-9629. ; 3:12
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Tidskriftsartikel (refereegranskat)abstract
- The most-efficient solar cells use Pb-based halide perovskites; however, their toxicity poses environmental and health risks. Here, the authors report an adsorbent that allows for sustainable Pb management in these devices. Despite the rapid development of perovskite solar cells (PSCs) toward commercialization, the toxic lead (Pb) ions in PSCs pose a potential threat to the environment, health and safety. Managing Pb via recycling represents a promising approach to mitigating its toxicity. However, managing Pb from commonly used organic solvents has been challenging due to the lack of suitable Pb adsorbents. Here, we report a new adsorbent for both separation and recovery of Pb from PSC pollutants. The synthesized iron-incorporated hydroxyapatite possesses a strongly negatively charged surface that improves electrostatic interaction through surface-charge delocalization, thus leading to enhanced Pb adsorption. We demonstrate the feasibility of a complete Pb management process, including the purification of Pb-containing non-aqueous solvents below 15 parts per 10(9), a level compliant with the standards of the US Environmental Protection Agency, as well as recycling of 99.97% of Pb ions by forming lead iodide.
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| 8. |
- Zhang, Tiankai, et al.
(författare)
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Ion-modulated radical doping of spiro-OMeTAD for more efficient and stable perovskite solar cells
- 2022
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Ingår i: Science. - : AMER ASSOC ADVANCEMENT SCIENCE. - 0036-8075 .- 1095-9203. ; 377:6605, s. 495-501
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Tidskriftsartikel (refereegranskat)abstract
- Record power conversion efficiencies (PCEs) of perovskite solar cells (PSCs) have been obtained with the organic hole transporter 2,2,7,7-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9-spirobifluorene (spiro-OMeTAD). Conventional doping of spiro-OMeTAD with hygroscopic lithium salts and volatile 4-tert-butylpyridine is a time-consuming process and also leads to poor device stability. We developed a new doping strategy for spiro-OMeTAD that avoids post-oxidation by using stable organic radicals as the dopant and ionic salts as the doping modulator (referred to as ion-modulated radical doping). We achieved PCEs of >25% and much-improved device stability under harsh conditions. The radicals provide hole polarons that instantly increase the conductivity and work function (WF), and ionic salts further modulate the WF by affecting the energetics of the hole polarons. This organic semiconductor doping strategy, which decouples conductivity and WF tunability, could inspire further optimization in other optoelectronic devices.
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| 9. |
- Ji-Young, Ahn, et al.
(författare)
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Aptamer microarray mediated capture and mass spectrometry identification of biomarker in serum samples.
- 2010
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 9:11, s. 5568-5573
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Tidskriftsartikel (refereegranskat)abstract
- Sensitive detection of molecular biomarkers in clinical samples is crucially important in disease diagnostics. This paper reports the developement of an aptamer microarray platform combined with sol-gel technology to identify low-abundance targets in complex serum samples. Because of the nanoporous structure of the sol-gel, a high capacity to immobilize the affinity specific aptamers is accomplished which allows binding and detection of target molecules with high sensitivity. The captured protein is digested in situ and the obtained digest was analyzed by ESI-MS without any interference from the affinity probe. TBP (TATA Box Protein) and its specific aptamers were chosen as a model system. A proof of concept with protein concentrations ranging between nanomolar to micromolar is reported, showing a good linearity up to 400 nM when characterized in an aptamer sandwich assay. Moreover, as low as 0.001% of target protein present in total serum proteins could be identified without any pretreatment step using ESI MS/MS mass spectrometry. We believe this novel strategy could become an efficient method for aptamer-based biomarker detection linked directly to mass spectrometry readout.
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