| 1. |
- Bai, Sai, et al.
(författare)
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Ethanedithiol Treatment of Solution-Processed ZnO Thin Films: Controlling the Intragap States of Electron Transporting Interlayers for Efficient and Stable Inverted Organic Photovoltaics
- 2015
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Ingår i: Advanced Energy Materials. - : Wiley-VCH Verlag. - 1614-6832 .- 1614-6840. ; 5:5, s. 1401606-
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Tidskriftsartikel (refereegranskat)abstract
- The surface defects of solution-processed ZnO films lead to various intragap states. When the solution-processed ZnO films are used as electron transport interlayers (ETLs) in inverted organic solar cells, the intragap states act as interfacial recombination centers for photogenerated charges and thereby degrade the device performance. Here, a simple passivation method based on ethanedithiol (EDT) treatment is demonstrated, which effectively removes the surface defects of the ZnO nanocrystal films by forming zinc ethanedithiolates. The passivation by EDT treatment modulates the intragap states of the ZnO films and introduces a new intragap band. When the EDT-treated ZnO nanocrystal films are used as ETLs in inverted organic solar cells, both the power conversion efficiency and stability of the devices are improved. The control studies show that the solar cells with EDT-treated ZnO films exhibit reduced charge recombination rates and enhanced charge extraction properties. These features are consistent with the fact that the modulation of the intragap states results in reduction of interfacial recombination as well as the improved charge selectivity and electron transport properties of the ETLs. It is further demonstrated that the EDT treatment-based passivation method can be extended to ZnO films deposited from sol-gel precursors.
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| 2. |
- Liang, Xiaoyong, et al.
(författare)
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Colloidal metal oxide nanocrystals as charge transporting layers for solution-processed light-emitting diodes and solar cells
- 2017
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Ingår i: Chemical Society Reviews. - : ROYAL SOC CHEMISTRY. - 0306-0012 .- 1460-4744. ; 46:6, s. 1730-1759
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Forskningsöversikt (refereegranskat)abstract
- Colloidal metal oxide nanocrystals offer a unique combination of excellent low-temperature solution processability, rich and tuneable optoelectronic properties and intrinsic stability, which makes them an ideal class of materials as charge transporting layers in solution-processed light-emitting diodes and solar cells. Developing new material chemistry and custom-tailoring processing and properties of charge transporting layers based on oxide nanocrystals hold the key to boosting the efficiency and lifetime of all-solution-processed light-emitting diodes and solar cells, and thereby realizing an unprecedented generation of high-performance, low-cost, large-area and flexible optoelectronic devices. This review aims to bridge two research fields, chemistry of colloidal oxide nanocrystals and interfacial engineering of optoelectronic devices, focusing on the relationship between chemistry of colloidal oxide nanocrystals, processing and properties of charge transporting layers and device performance. Synthetic chemistry of colloidal oxide nanocrystals, ligand chemistry that may be applied to colloidal oxide nanocrystals and chemistry associated with post-deposition treatments are discussed to highlight the ability of optimizing processing and optoelectronic properties of charge transporting layers. Selected examples of solution-processed solar cells and light-emitting diodes with oxide-nanocrystal charge transporting layers are examined. The emphasis is placed on the correlation between the properties of oxide-nanocrystal charge transporting layers and device performance. Finally, three major challenges that need to be addressed in the future are outlined. We anticipate that this review will spur new material design and simulate new chemistry for colloidal oxide nanocrystals, leading to charge transporting layers and solution-processed optoelectronic devices beyond the state-of-the-art.
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| 3. |
- Liang, Xiaoyong, et al.
(författare)
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Synthesis of Unstable Colloidal Inorganic Nanocrystals through the Introduction of a Protecting Ligand
- 2014
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Ingår i: Nano letters (Print). - : American Chemical Society. - 1530-6984 .- 1530-6992. ; 14:6, s. 3117-3123
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a facile and general strategy based on ligand protection for the synthesis of unstable colloidal nanocrystals by using the synthesis of pure p-type NiO nanocrystals as an example. We find that the introduction of lithium stearate, which is stable in the reaction system and capable of binding to the surface of NiO oxide nanocrystals, can effectively suppress the reactivity of NiO nanocrystals and thus prevent their in situ reduction into Ni. The resulting p-type NiO nanocrystals, a highly demanded hole-transporting and electron-blocking material, are applied to the fabrication of organic solar cells and polymer light-emitting diodes, demonstrating their great potential as an interfacial layer for low-cost and large-area, solution-processed optoelectronic devices.
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| 4. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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