Browsing by Author "Chen, Po-Chih"

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A novel high-strength, high-ductility and high-corrosion-resistance FeAlMnC low-density alloy
(2013-03-01)
Chen, Po-Chih
;
Chao, Chuen-Guang
;
Liu, Tzeng-Feng
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材料科學與工程學系
;
Department of Materials Science and Engineering
The as-quenched Fe-8.68 wt.% Al-30.5 wt.% Mn-1.85 wt.% C alloy is plasma-nitrided at 500 degrees C for 8 h. The nitrided layer obtained is 40 mu m thick and composed predominantly of AlN, with a small amount of Fe4N. The resultant surface hardness (1860 Hv), substrate hardness (550 Hv), ductility (33.6%) and corrosion resistance in 3.5% NaCl solution in the present nitrided alloy are far superior to those obtained previously in optimally nitrided high-strength alloy steels, as well as martensitic and precipitation-hardening stainless steels. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Perovskite film-wire transformation: Preparation, characterization and device application
(2019-06-01)
Chen, Yu-An
;
Yang, Sheng-Hsiung
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Chen, Po-Chih
;
Lin, Li-Jyuan
;
Wu, Zong-Yu
In this research, we demonstrate regular-type perovskite solar cells based on tungsten trioxide nanoparticles layer (WO3 NL) as the electron transport layer and methylammonium lead iodide nanowires (MAPbI(3) NWs) as the absorbing layer. By adjusting the amount of the anti-solvent DMF, MAPbI(3) NWs with different diameters ranging from 50 to 100 nm and lengths extending to several micrometers were obtained. [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) and cesium carbonate (Cs2CO3) were introduced between WO3 NL and MAPbI(3) NWs to improve film morphology and charge transfer ability. Meanwhile, spiro-MeOTAD doped with bis(trifluoromethane)sulfonimide lithium salt (Li-TFSI) was utilized to enhance hole transport. Finally, the perovskite solar cells with the configuration of ITO/WO3 NL/Cs2CO3/PCBM/MAPbI(3) NWs/spiro-MeOTAD/Au were fabricated and evaluated. To date, perovskite NWs treating with the proper amount of the anti-solvent DMF possess higher absorption, faster carrier transportation and lower recombination that are responsible for photovoltaic application.
Potassium-Doped Nickel Oxide as the Hole Transport Layer for Efficient and Stable Inverted Perovskite Solar Cells
(2019-09-01)
Chen, Po-Chih
;
Yang, Sheng-Hsiung
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照明與能源光電研究所
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Institute of Lighting and Energy Photonics
Organic/inorganic hybrid perovskites have received a great deal of attention in solar energy harvest due to their high absorbance in the visible range, long carrier diffusion length, and solution processability. It is extremely important to develop high-quality hole transport layer (HTL) to replace PEDOT:PSS for fabricating inverted perovskite solar cells (PSCs) with high power conversion efficiency (PCE) and device stability. Upon this consideration, we proposed potassium (K)-doped nickel oxide (NiOx) compact layer via the sol-gel process to improve the conductivity and to modify its work function. Inverted PSCs with the configuration of FTO/K:NiOx/Cs(0.05)FA(0.81)MA(0.14)Pb(I0.85Br0.15)(3)/TBABF(4)+PCBM/TIPD/Ag were fabricated and evaluated. We found that the device based on 3% K-doped NiOx showed the best performance with an optimized PCE of 17.05% and a high fill factor of 74%, and it retained about 80% of initial PCE value after 35 days storage. Our results provide a simple and effective approach to fabricate inverted PSCs with high efficiency and long-term stability for future production.
Structure and properties of gas-nitrided nanostructured FeAlMnC alloy
(2013-12-16)
Chen, Po-Chih
;
Chao, Chuen-Guang
;
Juang, Jenh-Yih
;
Liu, Tzeng-Feng
;
材料科學與工程學系
The as-quenched Fe-9Al-28Mn-1.8C (in wt.%) alloy was directly gas-nitrided at 500 degrees C for 8 h, resulting in a similar to 30 mu m-thick nitrided layer. The nitrided layer consists predominantly of nano-crystalline AlN with a small amount of Fe4N. The nitrogen concentration at surface was extremely high up to similar to 17 wt.% (similar to 41 at.%). Consequently, the surface microhardness (1700 Hv), substrate hardness (550 Hv), ductility (33.2%) and corrosion resistance in 3.5% NaCl solution of the present gas-nitrided alloy are far superior to those obtained previously for the optimally gas-nitrided or plasma-nitrided high-strength alloy steels, as well as martensitic and precipitation-hardening stainless steels. Moreover, it is very novel that the nitrided layer almost remained coherent and adhered well with the matrix after tensile test. Additionally, the present gas nitriding appeared to overcome the edge effects commonly encountered in plasma nitriding treatments for metals. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.