http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/91864 2026-10-04T20:37:18Z http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/94267 標題: 高性能凡德瓦高介電材料雙閘極二硫化鉬場效電晶體; High Performance of Dual-gated Molybdenum Disulfide Field Effect Transistor Enabled by van der Waals High-κ Dielectric Material 作者: 曾楷崴; Kai-Wei Tseng 摘要: 由於傳統介電材料如氧化鋁(Al2O3)和二氧化矽(SiO2)具有較高的熔點，直接通過熱蒸鍍在二維材料上沉積氧化層可能會導致破壞。因此，三氧化二銻(Sb2O3)由於其獨特的材料性質，可以作為二硫化鉬(MoS2)場效電晶體的閘極氧化層。三氧化二銻具有高介電常數(11.5)，其分子間透過凡德瓦力相互結合，在高真空(10-6 Torr)條件下於186℃昇華。三氧化二銻分子是雙環籠(bicyclic cage)結構，且無懸鍵結構，與二硫化鉬在界面處形成凡德瓦接觸，相較於傳統的氧化層提供了更卓越的介電性能。 在本研究中，該元件在室溫(T= 298K)下的上閘極(VTG)工作範圍為±1 V。最大汲極-源極電流(IDS)為0.21 µA，並展示出高達106的開關比。此元件的臨界電壓(VTH)為0.0088 V，次臨界擺幅(SS)為86.1 mV/dec，載子遷移率為13.5 cm2/Vs，遲滯為24mV。在常關態(normally-off state)的元件中，施加+8V的背閘極(VBG)，變為常開態(normally-on state)，IDS為0.74 µA，相比於常關態，載子遷移率提升355倍，遲滯僅為6.51mV。所有性能均具有高度競爭力，代表了在二維材料CMOS元件發展方面有顯著進步。; Due to the high melting point for the conventional dielectric material such as aluminum oxide (Al2O3) and silicon dioxide (SiO2), depositing oxide layers on two-dimensional materials directly via thermal evaporator may lead to damage. Therefore, antimony trioxide (Sb2O3), a high dielectric constant (11.5) material, can be the oxide layer in molybdenum disulfide (MoS2) field-effect transistors because of its unique material properties which molecules are bonded by van der Waals force and sublime at 186℃ in high vacuum (10-6 Torr) condition. Sb2O3 molecules are bicyclic cage structure which is free-dangling bond and form van der Waals contacts with MoS2 at the interface, offering superior performance compared to conventional oxide layers. In this study, the device has an applied range of ±1V for top gate (VTG) at room temperature (T = 298K). The maximum drain-source current (IDS) is 0.21 µA, and it exhibits a high on/off ratio of up to 106. The threshold voltage (VTH) for this device is 0.0088 V, the subthreshold swing (SS) is 86.1 mV/dec, the carrier mobility is 13.5 cm²/Vs and hysteresis is 24 mV. In a normally-off device, applying +8V to the back gate (VBG) switches it to a normally-on state. The IDS reaches 0.74 µA, which carrier mobility is 355 times larger than normally-off state, with a hysteresis of only 6.51 mV. All the performance are highly competitive, which represents significant progress in the development of two-dimensional material CMOS devices. 2024-01-01T00:00:00Z http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/98948 標題: 開發微波頻段電磁干擾量測系統暨檢測石墨烯複合材料電磁屏蔽效果; Development of a Microwave-Band EMI Measurement System and Evaluation of Electromagnetic Shielding Effectiveness of Graphene Composites 作者: 馬渝翔; Yu-Hsiang Ma 摘要: 科技的進步飛速，其中半導體產業的發展可以說是所有研究的基礎。半導體元件內部的電晶體密度提高，元件之間的距離也不斷縮小，追求效能提升的同時，電磁干擾的問題卻也日益嚴重，因此出現了各種解決電磁干擾的方法，包括改變電路佈局、元件的擺放位置或是使用電磁屏蔽材料。電磁屏蔽材料的研發需要不斷的透過實際量測數據進行反饋，並根據量測結果修正材料的製作參數，因此電磁干擾之量測系統的量測成本和速度是研究電磁屏蔽材料的關鍵，若每次量測都使用租借成本昂貴且排程時間冗長的電波暗室，將不利材料的研發進度。 本論文提出一套電磁干擾近場掃描量測系統，利用電壓隨耦器(Voltage Follwer)電路，創造出頻率可控的電磁輻射源，量測平台符合國際IC電磁干擾量測標準IEC 61967-1定義的10 cm × 10 cm四層板PCB，以及IEC 61967-3晶片表面掃描的量測規範，可快速且有效的量測各種電磁屏蔽材料於不同頻率下的屏蔽效率，頻率範圍含括IEC 61967-3所訂定之規範。此量測系統具有高度靈活性，既可量測薄膜型態的電磁屏蔽材料，也可將屏蔽材料封裝在IC上再進行量測，可在材料開發的早期階段就快速取得大量的電磁屏蔽效率量測數據，建立材料製作參數與屏蔽效能的對應關係，大幅提升屏蔽材料的研發速度。; The advancement of technology is growing rapidly, and one of the most important industries is semiconductor. As the density of transistors within semiconductor devices continues to increase and the spacing between chips decreases, the issue of electromagnetic interference (EMI) has become increasingly severe. Various methods to mitigate EMI have been proposed, including modifications to circuit layout, adjustments to chips placement on the circuit board, and the use of electromagnetic shielding materials. The development of EMI shielding materials requires continuous feedback through actual measurement data. Therefore, the cost and efficiency of EMI measurement systems are critical to the research and development of shielding materials. Anechoic chambers, which are expensive to build and takes long scheduling times to rent it, is not a good choice in early stage of material development. This work proposes a near-field EMI scanning measurement system that utilizes a voltage follower circuit to generate an electromagnetic radiation source with tunable frequency. The measurement platform complies with the international standard IEC 61967-1 for EMI testing of integrated circuits, specifically a 10 cm 10 cm four-layer PCB, as well as the IEC 61967-3 standard for IC surface scanning. The system enables effective evaluation of the shielding effectiveness of various materials across a wide frequency range, fully covering the specifications defined by IEC 61967-3. This measurement system offers high flexibility, allowing both the characterization of film-type shielding materials and the shielding materials directly packaged onto ICs. It help collecting shielding effectiveness data during the early stage of material development, enabling the establishment of correlations between fabrication parameters and shielding performance, significantly accelerating the R&D process of EMI shielding materials. 2025-01-01T00:00:00Z http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/103750 標題: 設計開發以自動突聚焦超穎透鏡為基礎之微型光聲顯微鏡; Metasurface-Generated Abrupt Autofocusing Beam for Miniaturized Photoacoustic Microscope 作者: 謝祖恩; Zu-En Hsieh 摘要: 光聲成像 (Photoacoustic imaging, PAI) 近年已成為生醫領域中重要的研究方向與應用工具，該技術透過脈衝雷射激發組織產生超音波訊號，再由超音波換能器進行偵測，透過特定光波長脈衝，PAI可在無需標記 (label-free) 的情況下實現血氧與脂肪等生理資訊成像，兼具高光學對比且較純光學系統擁有更好的穿透能力。然而，聲學解析度光聲顯微鏡（Acoustic-resolution photoacoustic microscopy, AR-PAM）通常仰賴體積較大的光學元件與複雜的光學對準機制，導致系統尺寸龐大，限制其在臨床應用與內視鏡發展上的可行性。因此，在維持AR-PAM解析度的同時實現系統微型化，仍為一項關鍵挑戰。本研究提出一種自動突聚焦光聲顯微鏡(AAF-PAM)，其利用光學超穎透鏡（Optical Metalens）所產生之自動突聚焦（Abrupt Autofocusing, AAF）雷射光束來進行微型化，AAF特殊中空光學結構可提供單晶超音波換能器的置入空間，達到傳統AR-PAM光學元件功能的同時大幅縮小探頭體積，並且因整體整合於三軸自動掃描系統中，AAF-PAM可將A-scan訊號重建為最大強度投影與深度影像。在實驗驗證中，所設計之直徑3 mm超穎透鏡成功產生自動突聚焦光束，該光束最大中空結構直徑為1 mm，並可置入中心頻率為20 MHz、-6 dB頻寬約為13 MHz、有效面積0.75 × 0.75 mm2、長度8 mm的方形單晶超音波探頭並於純水環境下進行光聲成像測試，結果顯示AAF-PAM具橫向解析度為165.6 ± 9.4 μm、縱向解析度109.5 ± 30.0 µm，優於本研究所用 20 MHz對應的理論AR-PAM解析度，且能穩定重建葉脈、鼠尾等生物樣本影像。此外，本系統亦為未來微型化光聲內視鏡（Photoacoustic endoscopy, PAE）及微型AR-PAM腦部動態影像應用奠定基礎。綜合而言，本研究證實超穎透鏡所產生之自動突聚焦光束可微型化AR-PAM，不僅突破傳統光學系統尺寸與整合限制，亦具備高度擴展性，展現其於醫學檢測及精準醫療等領域的應用潛力。; Photoacoustic imaging (PAI) has recently become an important research direction and a powerful tool in the biomedical field. It relies on pulsed laser excitation to generate ultrasonic signals that are subsequently detected by an ultrasound transducer. By selecting an appropriate optical wavelength, PAI enables label-free imaging of physiological parameters such as blood oxygenation and lipid distribution, while providing both high optical contrast and better deep tissue penetration compared with pure optical systems like OCT. However, acoustic-resolution photoacoustic microscopy (AR-PAM) typically depends on bulky optical components and complex optical alignment, resulting in a large system size that limits its feasibility for clinical applications and endoscopic integration. Therefore, achieving system miniaturization while maintaining AR-PAM-level resolution remains a critical challenge. In this thesis, an abrupt autofocusing photoacoustic microscope (AAF-PAM) is proposed, which utilizes an abrupt autofocusing (AAF) beam generated by an optical metalens to enable system miniaturization. The unique hollow region of the AAF beam provides sufficient space for the integration of a single-element ultrasound transducer, allowing the system to preserve the functionality of conventional AR-PAM while significantly reducing the probe size. By integrating the system with a three-axis automated scanning platform, the AAF-PAM is capable of reconstructing A-scan signals into maximum intensity projection (MIP) images and depth images. In the experimental validation, the designed metalens with a diameter of 3 mm successfully generates the AAF beam, which exhibits a maximum hollow diameter of 1 mm. This configuration enables the insertion of a square single-crystal ultrasound transducer with a center frequency of 20 MHz, a -6 dB bandwidth of approximately 13 MHz, an active area of 0.75 × 0.75 mm², and a length of 8 mm. Photoacoustic imaging experiments were conducted in a water environment to evaluate system performance. The results demonstrate that the AAF-PAM system achieves a lateral resolution of 165.6 ± 9.4 μm and an axial resolution of 109.5 ± 30.0 µm, comparable to those of conventional AR-PAM systems. In addition, the system is capable of stably reconstructing biological structures such as leaf venation and mouse tail vasculature, confirming its imaging capability. Furthermore, this system lays the foundation for future developments in miniaturized photoacoustic endoscopy (PAE) and compact AR-PAM systems for functional brain imaging. In summary, this thesis verifies that metalens-generated AAF beams provide an effective approach for miniaturizing AR-PAM. The proposed design overcomes the size and integration limitations of conventional optical systems, while offering high scalability and strong potential for applications in medical diagnostics and precision medicine. 2026-01-01T00:00:00Z http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/104779 標題: 苄胺衍生物自發性氧化反應之動力學研究; Kinetic Study on the Spontaneous Oxidation of Benzylamine Derivatives 作者: 洪郁雯; Yu-Wen Hung 摘要: 苄胺氧化反應(benzylamine oxidation reaction; BOR)可作為動力學緩慢且產物價值較低之產氧反應(oxygen evolution reaction; OER)的替代陽極反應，不僅能於溫和條件下合成具有高附加價值之苯甲腈(benzonitrile)，亦可降低電解系統之能量需求，然而現有直接電催化BOR多於鹼性水系電解液中施加陽極電位，以驅動Ni(OH)2氧化形成具BOR催化活性之NiOOH，雖然NiOOH之生成可促進苄胺氧化，但其形成與持續再生所需之鹼性水系環境及陽極電位，可能促使BOR過程之中間體苯甲亞胺(benzylimine)發生水解反應，生成苯甲醛(benzaldehyde)，而苯甲醛可進一步與未反應之苄胺進行縮合反應，形成N-亞苄基苄胺(N-benzylidenebenzylamine; N-BB)，此外，目標產物苯甲腈亦可能經逐步水解，先形成苯甲醯胺(benzamide)，再進一步轉化為苯甲酸(benzoic acid)，導致其選擇性降低，因此NiOOH之生成與持續再生所需之反應條件，與BOR中間體及目標產物之穩定性難以同時兼顧。 為解決上述問題，本研究提出結合亞鐵氰化物/鐵氰化物(Ferro/Ferri; [Fe(CN)6]4−/[Fe(CN)6]3−)液態氧化還原儲庫(redox reservoir; RR)與Ni(OH)2/NiOOH固態RR之混合式RR系統，於電化學階段，以濺鍍銀(Ag)之氣體擴散電極(gas diffusion electrode; GDE)作為陰極工作電極，進行二氧化碳還原反應(CO2 reduction reaction; CO2RR)生成含一氧化碳(CO)與氫氣(H2)之合成氣(syngas)，同時Ferro於陽極氧化為Ferri以暫時儲存氧化當量，隨後Ferri將Ni(OH)2氧化為NiOOH，使氧化當量由液態RR轉移至固態RR，最後，預先生成之NiOOH在無外加電位且未添加電解液之純苄胺中驅動BOR，藉此將NiOOH之生成環境與苄胺氧化環境分離，並於十個循環中實現高達99.06 μmol min−1之苯甲腈平均生成速率，所搭配之CO2RR於−20、−30、−60 mA cm−2之電流密度下，CO法拉第效率皆可維持於70%以上。 此外，本研究利用X光繞射(X-ray diffraction; XRD)分析證實，所使用之Ni(OH)2為β相，且β-Ni(OH)2於氧化過程中會先轉變為β-NiOOH，並於進一步氧化後形成γ-NiOOH，X光吸收近邊結構(X-ray absorption near-edge structure; XANES)比較結果顯示，γ-NiOOH具有較高之平均Ni氧化態，延伸X光吸收精細結構(extended X-ray absorption fine structure; EXAFS)擬合結果顯示，γ-NiOOH之Ni–O與Ni–Ni鍵長分別為1.88與2.81 Å，均短於β-NiOOH之1.90與2.84 Å，動力學分析結果顯示，由β-NiOOH與γ-NiOOH催化之BOR皆遵循一級反應動力學，其中以γ-NiOOH催化BOR時之反應速率常數為0.1203 min−1，高於β-NiOOH之0.1057 min−1，理論計算結果顯示，γ-NiOOH催化BOR時，速率決定步驟之活化能障為1.54 eV，低於β-NiOOH之1.95 eV，與實驗所得之動力學趨勢一致，說明以γ-NiOOH催化BOR時有較快之動力學，最後，不同對位取代苄胺衍生物於γ-NiOOH作用下之氧化反應速率常數，分別為4-甲氧基苄胺之0.1564 min−1、4-甲基苄胺之0.1389 min−1及4-氟苄胺之0.0860 min−1，相較於未取代苄胺(0.1203 min−1)，推電子取代基之存在可提高氧化反應速率，而拉電子取代基之存在則使反應速率降低，顯示取代基電子效應會影響BOR動力學，並展現γ-NiOOH催化不同苄胺衍生物氧化之通用性。; The benzylamine oxidation reaction (BOR) can serve as an alternative anodic reaction to the kinetically sluggish oxygen evolution reaction (OER), which produces relatively low-value oxygen (O2). BOR not only enables the synthesis of high-value benzonitrile under mild conditions but also reduces the energy demand of the electrolysis system. However, conventional direct electrocatalytic BOR is typically conducted in alkaline aqueous electrolytes under an applied anodic potential to oxidize Ni(OH)2 to NiOOH, which is catalytically active toward BOR. Although the formation of NiOOH facilitates benzylamine oxidation, the alkaline aqueous environment and anodic potential required for its formation and continuous regeneration may promote the hydrolysis of benzylimine, an intermediate in the BOR process, to benzaldehyde. Benzaldehyde can subsequently undergo condensation with unreacted benzylamine to form N-benzylidenebenzylamine (N-BB). In addition, the target product benzonitrile may undergo stepwise hydrolysis, first to benzamide and subsequently to benzoic acid, thereby lowering the selectivity toward benzonitrile. Therefore, the reaction conditions required for the formation and continuous regeneration of NiOOH are difficult to reconcile with those required to maintain the stability of the BOR intermediate and the target product. To address this issue, a hybrid redox reservoir (RR) system combining a ferrocyanide/ferricyanide (Ferro/Ferri; [Fe(CN)6]4−/[Fe(CN)6]3−) liquid RR with a Ni(OH)2/NiOOH solid RR was developed in this study. During the electrochemical stage, a silver-sputtered gas diffusion electrode (Ag-GDE) was employed as the cathodic working electrode for the CO2 reduction reaction (CO2RR), producing syngas comprising carbon monoxide (CO) and hydrogen (H2). Simultaneously, Ferro was oxidized to Ferri at the anode, thereby temporarily storing oxidation equivalents in the liquid RR. Ferri subsequently oxidized Ni(OH)2 to NiOOH, transferring the stored oxidation equivalents from the liquid RR to the solid RR. Finally, the pre-generated NiOOH drove BOR in neat benzylamine without an externally applied potential and without added electrolyte, thereby separating the reaction environment for NiOOH generation from that for benzylamine oxidation. Over ten cycles, an average benzonitrile formation rate of 99.06 μmol min−1 was achieved. Meanwhile, the coupled CO2RR maintained CO Faradaic efficiencies above 70% at current densities of −20, −30, and −60 mA cm−2. Furthermore, X-ray diffraction (XRD) analysis confirmed that the Ni(OH)2 used in this study was in the β phase. During oxidation, β-Ni(OH)2 was first transformed into β-NiOOH, which subsequently converted into γ-NiOOH upon further oxidation. X-ray absorption near-edge structure (XANES) analysis revealed that γ-NiOOH exhibited a higher average Ni oxidation state. Extended X-ray absorption fine structure (EXAFS) fitting further showed that the Ni–O and Ni–Ni bond lengths of γ-NiOOH were 1.88 and 2.81 Å, respectively, both shorter than the corresponding values for β-NiOOH (1.90 and 2.84 Å). Kinetic analysis showed that BOR catalyzed by both β-NiOOH and γ-NiOOH followed first-order kinetics. For BOR catalyzed by γ-NiOOH, the rate constant was 0.1203 min−1, higher than the corresponding value obtained with β-NiOOH (0.1057 min−1). Theoretical calculations showed that the activation barrier for the rate-determining step of BOR catalyzed by γ-NiOOH was 1.54 eV, lower than the corresponding barrier for β-NiOOH-catalyzed BOR (1.95 eV). This result was consistent with the experimentally observed kinetic trend, indicating that BOR catalyzed by γ-NiOOH exhibited faster kinetics than that catalyzed by β-NiOOH. Finally, the oxidation rate constants of different para-substituted benzylamine derivatives in the presence of γ-NiOOH were 0.1564 min−1 for 4-methoxybenzylamine, 0.1389 min−1 for 4-methylbenzylamine, and 0.0860 min−1 for 4-fluorobenzylamine. Relative to unsubstituted benzylamine (0.1203 min−1), derivatives bearing electron-donating substituents exhibited higher oxidation rate constants, whereas the derivative bearing an electron-withdrawing substituent exhibited a lower rate constant. These results demonstrate that substituent electronic effects influence BOR kinetics and further establish the general applicability of γ-NiOOH to the oxidation of different benzylamine derivatives. 2026-01-01T00:00:00Z