化學系
Permanent URI for this communityhttp://rportal.lib.ntnu.edu.tw/handle/20.500.12235/57
國立臺灣師範大學化學系座落於公館校區理學院大樓。本系成立於民國五十一年，最初僅設大學部。之後於民國六十三年、七十八年陸續成立化學研究所碩士班和博士班。本系教育目標旨在培養化學專業人才與中等學校自然及化學專業師資，授課著重理論及應用性。本系所現有師資為專任教授25人，另外尚有與中央研究院合聘教授3位，在分析、有機、無機及物理化學四個學門的基礎上發展跨領域之教學研究合作計畫。此外，本系另有助教13位，職技員工1位，協助處理一般學生實驗及行政事務。學生方面，大學部現實際共322人，碩士班現實際就學研究生共174人，博士班現實際就學共55人。
本系一向秉持著教學與研究並重，近年來為配合許多研究計畫的需求，研究設備亦不斷的更新。本系所的研究計畫大部分來自國科會的經費補助。此外，本系提供研究生獎助學金，研究生可支領助教獎學金（TA）、研究獎學金（RA）和部分的個別教授所提供的博士班學生獎學金（fellowships）。成績優良的大學部學生也可以申請獎學金。
本校圖書館藏書豐富，除了本部圖書館外，分部理學院圖書館西文藏書現有13萬餘冊，西文期刊合訂本有911餘種期刊，將近約3萬冊。此外，西文現期期刊約450種，涵蓋化學、生化、生物科技、材料及其他科學類等領域。目前本系各研究室連接校園網路，將館藏查詢、圖書流通、期刊目錄轉載等功能，納入圖書館資訊系統中，並提供多種光碟資料庫之檢索及線上資料庫如Science Citation Index，Chemical Citation Index，Chemical Abstracts，Beilstein，MDL資料庫與STICNET全國科技資訊網路之查詢。
News
Browse
15 results
Search Results
Item Enhanced performance of photodetector and photovoltaic based on carrier reflector and back surface field generated by doped graphene(American Institute of Physics (AIP), 2012-08-13) C.-W. Chang; D.-Y. Wang; W.-C. Tan; I-S. Huang; I-S. Wang; Chia-Chun Chen; Y.-J. Yang; Y.-F. ChenWe report the influence of carrier reflector and back surface field generated by dopedgraphene on n-ZnO nanoridges/p-silicon photodetectors and silicon solar cells. It is found that the p-type graphene not only acts as an electron blocking layer, but also helps the collection of photogenerated holes. Quite surprisingly, the on/off ratio of the photodetector with the insertion of dopedgraphene can be increased by up to 40 times. Moreover, we demonstrate that typical silicon solar cells with the dopedgraphene, the cell efficiency can be enhanced by about 20%. Our approach would expand numerous applications for graphene-based optoelectronic devices.Item FeS2 Nanocrystal Ink as a Catalytic Electrode for Dye-Sensitized Solar Cells(Wiley-VCH Verlag, 2013-06-24) Y.-C. Wang; D.-Y. Wang; Y.-T. Jiang; H.-A. Chen; Chia-Chun Chen; K.-C. Ho; - H.-L. Chou; Chun-Wei ChenCalligraphic counter electrodes: An important photovoltaic application using FeS2 nanocrystal (NC) pyrite ink to fabricate a counter electrode as an alternative to Pt in dye-sensitized solar cells is demonstrated. FeS2 NC ink exhibits excellent electrochemical catalytic activity and remarkable electrochemical stability. ITO=indium-doped tin oxide.Item Low operation voltage macromolecular composite memory assisted by graphene nanoflakes(Royal Society of Chemistry, 2013-01-21) Y.-C. Lai; D.-Y. Wang; I-S. Huang; Y.-T. Chen; Y.-H. Hsu; T.-Y. Lin; H.-F. Meng; T.-C. Chang; Y.-J. Yang; Chia-Chun Chen; F.-C. Hsu; Y.-F. ChenThe trend towards simple and low-cost processing is one of the most important for macromolecular memory development. Here, bistable memory devices using a solution-processable active material, a mixture of graphene nanoflakes (GNFs) and insulating poly(vinyl alcohol) (PVA), are investigated, which serve as the first example for the direct integration of as-prepared nanoscale graphene into macromolecular memory devices through a one-step low-temperature processing method. Bistable electrical switching behavior and nonvolatile rewritable memory effects are realized by using an indium–tin-oxide/GNF–PVA/silver (ITO/GNF–PVA/Ag) sandwich structure. The resulting device exhibits low operation voltages of +1.4 V (turn-on) and −1.3 V (turn-off), which is promising for memory cells with low power consumptions. The programmable ON- and OFF-states possess a retention time of over 104 s and endure up to 107 read pulses. The carrier transport in the OFF- and ON-states follows the typical trap-limited space charge limited current and Ohmic laws, respectively. The asymmetric electrical switch behavior is therefore attributed to conducting filaments formed in the PVA layer assisted by the charged GNFs that induce the transition of the conductivity. Our study provides a potential approach for integrating as-prepared graphene into macromolecular memory devices with excellent performances through a simple solution-process.Item Enhanced charge extraction in inverted hybrid photovoltaic cells assisted by graphene nanoflakes(Royal Society of Chemistry, 2011-11-21) Y.-M. Sung; F.-C. Hsu; D.-Y. Wang; I.-S. Wang; Chia-Chun Chen; H.-C. Liao; W.-F. Su; Y.-F. ChenWe use graphene nanoflakes (GNFs) to greatly enhance the charge extraction out of a photoactive blend in inverted hybrid poly(3-hexylthiophene):(6,6)-phenyl C61butyric acid methyl ester (P3HT:PCBM)/ZnO-nanorod photovoltaic cells. Instead of a continuous film, solution processed GNFs with dimensions less than 200 nm � 200 nm are homogeneously scattered on top of the well-aligned ZnO-nanorods. Those GNFs play key roles, they serve as an electron drain to collect electron flow out to ZnO-nanorods, enhance the carrier mobility of the device and promote holes to drift toward the surface in contact with the cathode. As a result, there is a large enhancement in photocurrent and photovoltage of 35% and 27%, respectively, leading to an improved cell efficiency by up to about 100%.Item Solution-Processable Pyrite FeS2 Nanocrystals for the Fabrication of Heterojunction Photodiodes with Visible to NIR Photodetection(Wiley-VCH Verlag, 2012-07-03) D.-Y. Wang; Y.-T. Jiang; C.-C. Lin; S.-S. Li; Y.T. Wang; Chia-Chun Chen; C.-W. ChenA heterojunction photodiode with NIR photoresponse using solution processable pyrite FeS2 nanocrystal ink is demonstrated which has the advantages of earth-abundance and non-toxicity. The device consists of a FeS2 nanocrystal (NC) thin film sandwiched with semiconducting metal oxides with a structure of ITO/ZnO/FeS2 NC/MoO3/Au, which exhibits an excellent photoresponse with a spectral response extended to NIR wavelengths of up to 1150 nm and a high photocurrent/dark current ratio of up to 8000 at -1 V under AM1.5 illumination (100 mW cm−2).Item Type-II heterojunction organic/inorganic hybrid non-volatile memory based on FeS(2) nanocrystals embedded in poly(3-hexylthiophene)(IOP Publishing, 2011-07-27) C.-W. Lin; D.-Y. Wang; Y. Tai; Y.-T. Jiang; M.-C. Chen; Chia-Chun Chen; Y.-J. Yang; Y.-F. ChenElectrical bistable behaviour was demonstrated in memory devices based on n-type FeS2 nanocrystals (NCs) embedded in a p-type poly(3-hexylthiophene) (P3HT) matrix. An organic/inorganic hybrid non-volatile memory device with a type-II band alignment, fabricated by a spin-coating process, exhibited electrical bistable characteristics. The bistable behaviour of carrier transport can be well described through the space-charge-limited current model. The small amount of FeS2 NCs in this device serve as an excellent charge trapping medium arising from the type-II band alignment between FeS2 and P3HT. Our study suggests a new way to integrate non-volatile memory with other devices such as transistor or photovoltaic since the presented FeS2/P3HT offers a type-II band alignment.Item Enhanced Infrared Light Harvesting of Inorganic Nanocrystal Photovoltaic and Photodetector on Graphene Electrode(American Institute of Physics, 2011-06-27) C.-C. Lin; D.-Y. Wang; K.-H. Tu; Y.-T. Jiang; M.-H. Hsieh; Chia-Chun Chen; C.-W. ChenWe demonstrate an enhancement of infrared light harvesting of inorganic PbSnanocrystalphotovoltaic and photodetectordevices based on the transparent grapheneelectrode. Due to high infrared transparency of the grapheneelectrode with respect to indium tin oxide (ITO), the infrared photoresponse of the graphene-based device is superior to the ITO-based counterpart, in spite of a higher sheet resistance of the grapheneelectrode. The outstanding infrared characteristics of the devices based on the grapheneelectrode make it a promising candidate for infrared optoelectronic applications such as solar cells, imaging and sensing, or optical communication.Item Simple Replacement Reaction for the Preparation of Ternary Fe1?xPtRux Nanocrystals with Superior Catalytic Activity in Methanol Oxidation Reaction.(American Chemical Society, 2012-06-20) D.-Y. Wang; H.-L. Chou; Y.-C. Lin; F.-J. Lai; C.-H. Chen; J.-F. Lee; B.-J. Hwang; Chia-Chun ChenThe finding of new metal alloyed nanocrystals (NCs) with high catalytic activity and low cost to replace PtRu NCs is a critical step toward the commercialization of fuel cells. In this work, a simple cation replacement reaction was utilized to synthesize a new type of ternary Fe1–xPtRux NCs from binary FePt NCs. The detailed structural transformation from binary FePt NCs to ternary Fe1–xPtRux NCs was analyzed by X-ray absorption spectroscopy (XAS). Ternary Fe35Pt40Ru25, Fe31Pt40Ru29, and Fe17Pt40Ru43 NCs exhibit superior catalytic ability to withstand CO poisoning in methanol oxidation reaction (MOR) than do binary NCs (FePt and J-M PtRu). Also, the Fe31Pt40Ru29 NCs had the highest alloying extent and the lowest onset potential among the ternary NCs. Furthermore, the origin for the superior CO resistance of ternary Fe1–xPtRux NCs was investigated by determining the adsorption energy of CO on the NCs’ surfaces and the charge transfer from Fe/Ru to Pt using a simulation based on density functional theory. The simulation results suggested that by introducing a new metal into binary PtRu/PtFe NCs, the anti-CO poisoning ability of ternary Fe1–xPtRux NCs was greatly enhanced because the bonding of CO–Pt on the NCs’ surface was weakened. Overall, our experimental and simulation results have indicated a simple route for the discovery of new metal alloyed catalysts with superior anti-CO poisoning ability and low usage of Pt and Ru for fuel cell applications.Item Quantum Dot Light-Emitting Diode Using Solution-Processable Graphene Oxide as the Anode Interfacial Layer.(American Chemical Society, 2012-05-10) D.-Y. Wang; I.-S. Wang; I.-S. Huang; Y.-C. Yeh; S.-S. Li; K.-H. Tu; Chia-Chun Chen; C.-W. ChenIn this article, the solution processable graphene oxide (GO) thin film was utilized as the anode interfacial layer in quantum dot light emitting diodes (QD-LEDs). The QD-LED devices (ITO/GO/QDs/TPBi/LiF/Al) were fabricated by employing a layer-by-layer assembled deposition technique with the electrostatic interaction between GO and QDs. The thicknesses of GO thin films and the layer number of CdSe/ZnS QD emissive layers were carefully controlled by spin-casting processes. The GO thin films, which act as the electron blocking and hole transporting layer in the QD-LED devices, have demonstrated the advantage of being compatible with fully solution-processed fabrications of large-area printable optoelectronic devices.Item Efficient Light Harvesting by Photon Downconversion and Light Trapping in Hybrid ZnS Nanoparticles/Si Nanotips Solar Cells(American Chemical Society, 2010-10-26) C.-Y. Huang; D.-Y. Wang; C.-H. Wang; Y.-T. Chen; Y.-T. Wang; Y.-T. Jiang; Y.-J. Yang; Chia-Chun Chen; Y.-F. ChenA hybrid colloidal ZnS nanoparticles/Si nanotips p−n active layer has been demonstrated to have promising potential for efficient solar spectrum utilization in crystalline silicon-based solar cells. The hybrid solar cell shows an enhancement of 20% in the short-circuit current and approximately 10% in power conversion efficiency compared to its counterpart without integrating ZnS nanoparticles. The enhancement has been investigated by external quantum efficiency, photoluminescence excitation spectrum, photoluminescence, and reflectance to distinct the role of ZnS quantum dots for light harvesting. It is concluded that ZnS nanoparticles not only act as frequency downconversion centers in the ultraviolet region but also serve as antireflection coating for light trapping in the measured spectral regime. Our approach is ready to be extended to many other material systems for the creation of highly efficient photovoltaic devices.