The Experts below are selected from a list of 57852 Experts worldwide ranked by ideXlab platform
Jianghui Zheng - One of the best experts on this subject based on the ideXlab platform.
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Spin Coating free fabrication for highly efficient perovskite solar cells
Solar Energy Materials and Solar Cells, 2017Co-Authors: Jianghui Zheng, Meng Zhang, Xiaofan Deng, Chao Chen, Martin A Green, Shujuan Huang, Anita HobaillieAbstract:A Spin-Coating-free fabrication sequence has been developed for the fabrication of highly efficient organic-inorganic halide perovskite solar cells (PSCs). A novel blow-drying method is demonstrated to be successful in depositing high quality mesoporous TiO2 (mp-TiO2), methylammonium lead halide (CH3NH3PbI3) perovskite and spiro-MeOTAD layers. When combined with compact TiO2 (c-TiO2) deposited by spray pyrolysis which is also a Spin-Coating-free process, a stabilized power conversion efficiency exceeding 17% can be achieved for the glass/FTO/c-TiO2/mp-TiO2/ CH3NH3PbI3/spiro-MeOTAD/Au device. This is the highest efficiency for PSCs fabricated without the use of Spin-Coating to our knowledge. This method provides a pathway towards a scalable process for fabricating high-performance, large area and reproducible PSCs.
Yeong Don Park - One of the best experts on this subject based on the ideXlab platform.
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understanding solidification of polythiophene thin films during Spin Coating effects of Spin Coating time and processing additives
Scientific Reports, 2015Co-Authors: Jin Yeong Na, Boseok Kang, Yeong Don ParkAbstract:Spin-Coating has been used extensively in the fabrication of electronic devices; however, the effects of the processing parameters have not been fully explored. Here, we systematically characterize the effects of the Spin-Coating time on the microstructure evolution during semiconducting polymer solidification in an effort to establish the relationship between this parameter and the performances of the resulting polymer field-effect transistors (FETs). We found that a short Spin-Coating time of a few seconds dramatically improve the morphology and molecular order in a conjugated polymer thin film because the π-π stacking structures formed by the polymer molecules grow slowly and with a greater degree of order due to the residual solvent present in the wet film. The improved ordering is correlated with improved charge carrier transport in the FETs prepared from these films. We also demonstrated the effects of various processing additives on the resulting FET characteristics as well as on the film drying behavior during Spin-Coating. The physical properties of the additives are found to affect the film drying process and the resulting device performance.
Anita Hobaillie - One of the best experts on this subject based on the ideXlab platform.
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Spin Coating free fabrication for highly efficient perovskite solar cells
Solar Energy Materials and Solar Cells, 2017Co-Authors: Jianghui Zheng, Meng Zhang, Xiaofan Deng, Chao Chen, Martin A Green, Shujuan Huang, Anita HobaillieAbstract:A Spin-Coating-free fabrication sequence has been developed for the fabrication of highly efficient organic-inorganic halide perovskite solar cells (PSCs). A novel blow-drying method is demonstrated to be successful in depositing high quality mesoporous TiO2 (mp-TiO2), methylammonium lead halide (CH3NH3PbI3) perovskite and spiro-MeOTAD layers. When combined with compact TiO2 (c-TiO2) deposited by spray pyrolysis which is also a Spin-Coating-free process, a stabilized power conversion efficiency exceeding 17% can be achieved for the glass/FTO/c-TiO2/mp-TiO2/ CH3NH3PbI3/spiro-MeOTAD/Au device. This is the highest efficiency for PSCs fabricated without the use of Spin-Coating to our knowledge. This method provides a pathway towards a scalable process for fabricating high-performance, large area and reproducible PSCs.
Min Soo Park - One of the best experts on this subject based on the ideXlab platform.
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One-Step Preparation of Antireflection Film by Spin-Coating of Polymer/Solvent/Nonsolvent Ternary System
Chemistry of Materials, 2005Co-Authors: Min Soo ParkAbstract:An antireflection film was prepared by Spin-Coating of poly(methyl methacrylate) (PMMA) solution in chloroform in the presence of small amounts of nonsolvent alkanes. When the vapor pressure of a nonsolvent was lower than that of chloroform, a dense skin layer was formed because of the rapid solvent evaporation during Spin-Coating, whereas increasing the nonsolvent content below this layer resulted in a phase-separated structure. The phase-separated structure below the dense skin layer became a porous layer after the complete evaporation of both chloroform and nonsolvent. Since the film thickness after Spin-Coating was on the order of hundreds of nanometers, the size of the pores formed at the inner layer was also a few hundred nanometers. The two layers consisting of a dense skin layer and an inner porous layer exhibited excellent antireflection (AR) when coated on glass substrate. By a one-step procedure of Spin-Coating of PMMA, the film has high transmittance of over 98% at visible wavelengths. Further...
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breath figure patterns prepared by Spin Coating in a dry environment
Langmuir, 2004Co-Authors: Min Soo ParkAbstract:We introduce a novel method for fabricating breath figure patterns on a homopolymer film by Spin Coating of polymer solutions with various solvents. The homopolymers employed in this study were cellulose acetate butyrate, monocarboxylated end-functional polystyrene, and poly(methyl methacrylate). Breath figure patterns were generated even when a water-miscible solvent such as tetrahydrofuran (THF) was used as a solvent. We even succeeded in generating breath figure patterns by Spin Coating even under a dry environment (relative humidity less than 30%), when water was directly added into THF solution. With the combination of the Spin Coating method, pores with a few hundred nanometers to several micrometers have been generated. We found that the pore size becomes larger with increasing water content in THF solution and decreasing rotating speed. This is equivalent to increasing humidity and decreasing evaporation speed, respectively, in the conventional method, which is direct solvent evaporation under a h...
Jin Yeong Na - One of the best experts on this subject based on the ideXlab platform.
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understanding solidification of polythiophene thin films during Spin Coating effects of Spin Coating time and processing additives
Scientific Reports, 2015Co-Authors: Jin Yeong Na, Boseok Kang, Yeong Don ParkAbstract:Spin-Coating has been used extensively in the fabrication of electronic devices; however, the effects of the processing parameters have not been fully explored. Here, we systematically characterize the effects of the Spin-Coating time on the microstructure evolution during semiconducting polymer solidification in an effort to establish the relationship between this parameter and the performances of the resulting polymer field-effect transistors (FETs). We found that a short Spin-Coating time of a few seconds dramatically improve the morphology and molecular order in a conjugated polymer thin film because the π-π stacking structures formed by the polymer molecules grow slowly and with a greater degree of order due to the residual solvent present in the wet film. The improved ordering is correlated with improved charge carrier transport in the FETs prepared from these films. We also demonstrated the effects of various processing additives on the resulting FET characteristics as well as on the film drying behavior during Spin-Coating. The physical properties of the additives are found to affect the film drying process and the resulting device performance.