DSpace community: 永續去碳科技碩／博士學位學程

石墨烯功能化邊界態誘導二維半導體水平異質結之形成與電傳輸特性研究;Study of Electrical Transport Properties in Functionalized Graphene-Edge-Induced 2D Semiconductor Lateral Heterojunctions

title: 石墨烯功能化邊界態誘導二維半導體水平異質結之形成與電傳輸特性研究;Study of Electrical Transport Properties in Functionalized Graphene-Edge-Induced 2D Semiconductor Lateral Heterojunctions abstract: 隨著半導體製程尺寸逼近原子尺度，傳統矽基材料面臨嚴峻的短通道效應與漏電挑戰，二維材料因具備原子級厚度與優異的靜電控制能力，成為突破摩爾定律的關鍵材料。在眾多過渡金屬二硫屬化物中，二硫化鉬(MoS2) 因其高環境穩定性與合適的能隙脫穎而出。然而，傳統化學氣相沉積法（Chemical Vapor Deposition，CVD）在無圖案化基板上成長時常伴隨隨機成核與多層堆疊，難以精密控制成核位置與晶體形貌。本研究分為兩個主要階段。第一階段聚焦於低壓化學氣相沉積法（Low Pressure Chemical Vapor Deposition， LPCVD）生長單層MoS2之參數優化，系統性調控反應溫度、系統壓力、氣體流量與前驅物比例。實驗結果顯示，當鉬源(MoO3)劑量為25 mg且加熱至 790°C、系統壓力25 Torr、氬氣流量 80 sccm，並搭配700 mg 硫粉且硫源提前反應2分鐘，為最佳生長條件。此參數成功平衡了前驅物之質傳與表面擴散速率，可穩定獲得結晶品質優異、光致發光（PL）半高寬最優為75.68 meV且尺寸達28 µm 的正三角形單層單晶。第二階段則引入圖案化石墨烯輔助生長基板，利用微影與電漿蝕刻定義出石墨烯邊界，引導MoS2定向側向生長。為調控界面化學活性，研究對比了Ar/ H2 與引進氨氣的雙階段Ar/ H2+Ar/NH3退火處理。結果證實，在降低鉬源至15 mg的基礎下，單純使用 Ar/ H2退火在不同通道寬度下易呈現雙層結構，無法精準控制層數。相較之下，經由雙階段Ar/ H2+Ar/NH3高溫退火的樣品，D band增高且2D band下降，顯示石墨烯表面存在較多缺陷之活性位點，有利於前驅物的吸附與成核。此機制有效抑制了垂直堆疊，在2 µm至30 µm的通道寬度下，均能穩定重現結構均勻的單層MoS2連續膜。最後，在元件評估方面，研究發現石墨烯與藍寶石基板在經歷高溫製程後具備極強的界面鍵結力，導致傳統濕式轉印法面臨材料破損與層間斷裂之瓶頸。為規避轉印損耗，本研究直接於原始藍寶石基板上製備出頂閘極場效電晶體（Top-gate FET），順利確保了元件電學傳輸特性評估的可行性，為未來低接觸電阻之二維半導體界面工程提供了極具價值的製程指導方針。;As semiconductor technology approaches the atomic scale， conventional silicon-based materials face severe challenges associated with short-channel effects and leakage current. Owing to their atomic thickness and excellent electrostatic control， two-dimensional (2D) materials have emerged as promising candidates for extending device scaling beyond the limits of Moore’s law. Among various transition metal dichalcogenides (TMDCs)， molybdenum disulfide (MoS₂) has attracted considerable attention because of its high environmental stability and suitable bandgap. However， conventional chemical vapor deposition (CVD) on unpatterned substrates typically suffers from random nucleation and multilayer stacking， making it difficult to precisely control nucleation sites and crystal morphology. This study consists of two major stages. The first stage focuses on optimizing the growth parameters for monolayer MoS₂ using low-pressure chemical vapor deposition (LPCVD). The reaction temperature， chamber pressure， carrier gas flow rate， and precursor ratio were systematically optimized. The experimental results indicate that the optimal growth condition was achieved using a 25 mg MoO₃ precursor heated to 790 °C， a chamber pressure of 25 Torr， an Ar flow rate of 80 sccm， and 700 mg of sulfur powder with sulfur introduction initiated 2 minutes prior to growth. Under these conditions， a balance between precursor mass transport and surface diffusion was achieved， resulting in high-quality equilateral triangular monolayer MoS₂ single crystals with a minimum photoluminescence (PL) full width at half maximum (FWHM) of 75.68 meV and an average crystal size of 28 μm.In the second stage， patterned graphene was introduced as a growth template， where photolithography and plasma etching were employed to define graphene trench boundaries for guiding the oriented lateral growth of MoS₂. To regulate the interfacial chemical activity， conventional Ar/H₂ annealing was compared with a two-stage Ar/H₂ + Ar/NH₃ annealing process. Under a reduced MoO₃ dosage of 15 mg， conventional Ar/H₂ annealing tended to produce bilayer structures over different trench widths， making precise layer-number control difficult. In contrast， samples subjected to the two-stage Ar/H₂ + Ar/NH₃ annealing exhibited an increased D band intensity and decreased 2D band intensity， indicating the formation of additional defect-related active sites on the graphene surface that promoted precursor adsorption and nucleation. This mechanism effectively suppressed vertical stacking， enabling the reproducible growth of structurally uniform monolayer MoS₂ continuous films across trench widths ranging from 2 μm to 30 μm. Finally， device evaluation revealed that graphene formed extremely strong interfacial bonding with the sapphire substrate after high-temperature processing， posing significant challenges for conventional wet-transfer processes due to material damage and interlayer delamination. To avoid transfer-induced degradation， top-gate field-effect transistors (Top-gate FETs) were directly fabricated on the original sapphire substrate. This fabrication strategy establishes a feasible process for evaluating the electrical transport characteristics of graphene/MoS₂ heterostructures and provides valuable processing guidelines for future interface engineering of low-contact-resistance two-dimensional semiconductor devices.

四元中熵觸媒應用於電化學二氧化碳還原反應性能之探討;Study on Quaternary Medium-Entropy Catalysts for Electrochemical Carbon Dioxide Reduction

title: 四元中熵觸媒應用於電化學二氧化碳還原反應性能之探討;Study on Quaternary Medium-Entropy Catalysts for Electrochemical Carbon Dioxide Reduction abstract: 在日趨嚴重的氣候變遷背景下，二氧化碳(CO2)排放為其中備受關注的核心議題之一，除了探索減排路徑外，如何有效捕捉並利用CO2亦屬重要。電化學二氧化碳還原反應(CO2RR)是實現碳資源循環再利用之關鍵技術，其中甲酸因具備高能量密度與成熟的下游應用，被視為極具潛力的C1產物。然而。本研究以鉍(Bi)、鉛(Pb)、銅(Cu)、鋅(Zn)作為元素系統組成中熵氧化物觸媒，透過製程優化、導電網絡工程與組成調變之系統性研究，成功構築出兼具高選擇性與長期穩定性之電催化轉化甲酸之中熵觸媒。研究結果顯示，控制煅燒條件為600 °C並延長持溫時間至6小時，能有效抑制晶粒過度長大與團聚，並在維持多金屬元素均勻分佈的前提下，獲得具顆粒狀結構。研究進一步引入導電碳黑，不僅提升了催化顆粒的分散性，更大幅放大電化學活性表面積(ECSA)並降低電荷轉移阻抗(EIS)，在放大電流密度的同時，仍舊維持對甲酸的高選擇性，顯著提升整體反應速率。在組成調變方面，透過元素加倍與缺Bi設計，結果顯示Bi為維持該多四元中熵系統甲酸選擇性與反應穩定性之關鍵組成元素，隨著Bi含量的增加顯著地提升反應性能。最終實驗表明，採用 Bi 加倍並經上述最適煅燒條件(600°C/6 hr)煅燒之觸媒(Bi2PbCuZn)nO，在−1.1 V vs. RHE電位下進行連續30小時的恆電位測試，其甲酸法拉第效率(Faradaic Efficiency， FE)始終維持在91%以上，且總電流密度與LSV曲線於測試前後幾乎無衰退，展現出優異的操作穩定性。本研究初步證實中熵觸媒於CO2RR中具備應用潛力。;Against the backdrop of increasingly severe climate change， carbon dioxide (CO2) emissions have emerged as a critical issue of global concern. Beyond emission reduction， the effective capture and utilization of CO2 is of paramount importance. The electrochemical CO2 reduction reaction (CO2RR) represents a key technology for carbon resource recycling， and formic acid is considered a highly promising C1 product due to its high energy density and mature downstream applications. In this study， a quaternary medium-entropy oxide system comprising bismuth (Bi)， lead (Pb)， copper (Cu)， and zinc (Zn) was developed as an electrocatalytic platform for CO2 reduction to formic acid， exhibiting both high selectivity and long-term stability. Calcination at 600℃ with an extended 6-hour dwelling time effectively suppressed excessive grain growth and agglomeration， yielding an overlapping columnar structure while maintaining uniform elemental distribution. Introducing conductive carbon black further enhanced particle dispersion， expanded the electrochemical active surface area (ECSA)， and reduced charge transfer resistance， thereby accelerating the reaction rate while preserving formic acid selectivity. Compositional tuning via element-doubling and Bi-deficient designs demonstrated Bi to be the key constituent for maintaining formic acid selectivity and reaction stability; its absence led to a marked decline in both performance and selectivity. The optimized catalyst， Bi-doubled (Bi2PbCuZn)nO calcined at 600℃/6 hr， underwent a continuous 30-hour potentiostatic test at −1.1 V (vs. RHE)， maintaining a Faradaic efficiency (FE) for formic acid consistently above 91%， with negligible degradation in current density or LSV curves. This study preliminarily validates the application potential of medium-entropy catalysts in CO2RR.

廬山地熱礦物特徵及其隱示;Mineralogical Characteristics and Geothermal Implications of the Lushan Area

title: 廬山地熱礦物特徵及其隱示;Mineralogical Characteristics and Geothermal Implications of the Lushan Area abstract: 廬山溫泉位在中央山脈板岩區，屬於非火山型造山帶地熱區。本研究針對其中的馬海濮溫泉露頭蒸氣口附近沉澱的礦物進行定性研究，利用X光繞射儀與拉曼光譜儀並使用RRUFF和ICDD資料庫進行礦物鑑定；以實體顯微鏡、掃描式電子顯微鏡搭配能量頻譜分析儀了解礦物晶癖、彼此生長關係以及元素組成。本研究亦分析附近溫泉水成分並使用地化模擬軟體PHREEQC，探討礦物沉澱機制。研究結果顯示：馬海濮溫泉區的熱液礦物包含：天然鹼、硫磺、鐵鈉礬、白鈉鎂礬、無水硫酸鈉、葉綠礬、鎂葉綠礬、六水鎂礬、瀉利鹽、鐵明礬、斜鈉明礬、及黃鉀鐵礬。其中，黃鉀鐵礬與斜鈉明礬一般產於酸性環境而天然鹼和無水硫酸鈉產於鹼性環境。廬山地區原始熱液的pH值約在6.9-8.2之間、硫酸根濃度低、亦無火山區活躍的H₂S脫氣的硫來源，噴氣口附近的含硫礦物生長機制極為特殊。為釐清其形成緣由，本研究使用PHREEQC-水化學熱力學模擬軟體，結果顯示：地下熱液經歷閃發濃縮無法產生含硫礦物。唯有加上圍岩的黃鐵礦氧化分解釋放硫酸根、使pH值降低才有可能沉澱明礬石與黃鉀鐵礬。明礬石僅在pH值高於4才能沉澱；黃鉀鐵礬無論混入乾季或溼季溪水的情境下皆維持過飽和狀態產生沉澱。PHREEQC模擬顯示中性至鹼性的廬山熱液環境，仍可透過圍岩黃鐵礦氧化產酸而生成含硫礦物。關鍵字：廬山溫泉區、熱液礦物、黃鉀鐵礬、PHREEQC;The Lushan hot springs， located within the slate belt of the Central Range， represent a non-volcanic， orogenic-belt geothermal system. This study examines minerals precipitated near the fumarolic vents of the Mahaipu hot spring outcrop， using X-ray diffraction (XRD) and Raman spectroscopy—referenced against the RRUFF and ICDD databases—for mineral identification， and optical/scanning electron microscopy (SEM-EDS) to characterize mineral habit， paragenesis， and elemental composition. Spring water chemistry was also analyzed， and PHREEQC geochemical modeling was applied to evaluate mineral precipitation mechanisms. The identified hydrothermal minerals include trona， sulfur， sideronatrite， bloedite， thenardite， copiapite， magnesiocopiapite， hexahydrite， epsomite， halotrichite， tamarugite， and jarosite. Jarosite and tamarugite typically form under acidic conditions， while trona and thenardite form under alkaline conditions. However， the original hydrothermal fluid at Lushan has a near-neutral to weakly alkaline pH (6.9–8.2)， low sulfate concentration， and no active volcanic H₂S source， making the occurrence of sulfur-bearing minerals near the vents anomalous. PHREEQC simulations show that flash evaporation alone cannot produce these minerals; instead， sulfate released from oxidative dissolution of wall-rock pyrite lowers the fluid pH， enabling precipitation of alunite and jarosite. Alunite precipitates only above pH ~4， while jarosite remains supersaturated—and thus continues to precipitate—regardless of dry- or wet-season stream water mixing. These results indicate that although the Lushan hydrothermal system is fundamentally near-neutral to alkaline， localized acidification from wall-rock pyrite oxidation drives the formation of sulfur-bearing minerals， explaining their unusual occurrence near the fumarolic vents.

貨櫃陸運溫室氣體減量策略之有效性評估;貨櫃陸運溫室氣體減量策略之有效性評估

title: 貨櫃陸運溫室氣體減量策略之有效性評估;貨櫃陸運溫室氣體減量策略之有效性評估 abstract: 隨著全球淨零排放政策推動、供應鏈低碳轉型及企業永續治理要求日益提升，物流運輸已成為企業溫室氣體管理的重要環節。其中，貨櫃陸運因高度依賴柴油車輛，且普遍存在裝載率不足、空車回送比例偏高、交通壅塞及怠速等待等營運問題，使其成為供應鏈中重要的溫室氣體排放來源。近年來，歐盟碳邊境調整機制（CBAM）、企業 Scope 3 排放揭露要求，以及我國「2050淨零排放路徑及策略總說明」等政策相繼推動，使貨櫃陸運減碳不僅關係物流業者營運效率，更直接影響企業供應鏈碳管理與國際競爭力。因此，如何建立具一致性、可比較性與可操作性的減碳策略評估方法，已成為物流運輸永續發展的重要課題。本研究以貨櫃陸運為研究對象，旨在分析貨櫃陸運之主要排放來源與影響因素，比較不同減碳策略之減量效果與實施可行性，並建構一套適用於貨櫃陸運之溫室氣體減量策略有效性評估架構，以提供物流業者、製造業及政府部門於供應鏈碳管理與減碳決策之參考。研究方法首先透過文獻回顧，整理國際主要溫室氣體量化標準與運輸排放計算方法，包括 IPCC Guidelines、GHG Protocol、GLEC Framework、ISO 14083及相關物流減碳文獻，歸納貨櫃陸運排放來源、量化方法及減碳策略。其次，建立以活動數據、排放係數及全球暖化潛勢值（GWP）為基礎之排放量計算模型，並採用 Tank-to-Wheel（TTW）作為系統邊界，以 gCO₂e／ton-km 及 gCO₂e／TEU-km 為功能單位，提升不同策略間之可比較性。同時導入資料品質指標（Data Quality Indicator， DQI）、敏感度分析及不確定度分析，以檢驗模型之穩健性與可信度。本研究顯示，裝載率不足、空車回送及車輛怠速等待為影響貨櫃陸運排放強度之主要因素。其中，營運改善策略如提升裝載率、降低空車率、路線最佳化及Eco-driving等措施，具有投資成本較低、短期導入容易及減碳效益明顯等優勢；相較之下，電動貨櫃車、氫能車及多式聯運等技術與系統轉型策略，雖具較高之長期減碳潛力，但仍受限於基礎設施建置、能源供應及投資成本等因素。分析結果顯示，提升裝載率約可降低10%至30%之單位運輸排放，降低空車率約可減少5%至20%，路線最佳化及Eco-driving約可降低5%至15%；而車輛電動化及多式聯運等策略，長期減碳潛力可達40%至70%以上。敏感度分析結果指出，裝載率、空車率及燃油效率為影響排放結果最重要之關鍵參數，其中裝載率變動對排放強度影響最為顯著；不確定度分析則顯示，在合理之活動數據變異範圍內，研究所建立之排放量化模式仍具有良好穩健性，顯示本研究所建構之評估架構具備實務應用與推廣價值。本研究之主要貢獻，在於整合國際溫室氣體量化標準及物流運輸管理方法，建立一套適用於貨櫃陸運之減碳策略有效性評估架構，使不同減碳措施能於一致之功能單位、系統邊界及排放量化方法下進行比較。此外，本研究進一步將物流減碳成果連結至企業 Scope 3 供應鏈碳管理，強化減碳績效歸屬與資訊揭露之應用價值，可作為物流業者規劃減碳策略、企業推動供應鏈碳管理，以及政府制定低碳物流政策之重要參考，亦可作為後續相關研究發展之基礎。關鍵字：貨櫃陸運、溫室氣體排放、減碳策略、Scope 3、GLEC Framework、ISO 14083、物流減碳、供應鏈碳管理;With the advancement of global net-zero emissions policies， the low-carbon transformation of supply chains， and increasing demands for corporate sustainability， logistics and transportation have become a crucial link in corporate greenhouse gas management. Containerized land transportation， heavily reliant on diesel vehicles and plagued by issues such as underloading， high rates of empty return trips， traffic congestion， and idling， has become a significant source of greenhouse gas emissions in the supply chain. In recent years， the EU′s Carbon Border Adjustment Mechanism (CBAM)， the Corporate Scope 3 emissions disclosure requirements， and Taiwan′s 2050 Net-Zero Emissions Pathway and Strategy Overview have all contributed to the development of policies that have made carbon reduction in containerized land transportation not only crucial for logistics operators′ operational efficiency but also directly impact corporate supply chain carbon management and international competitiveness. Therefore， establishing a consistent， comparable， and actionable methodology for evaluating carbon reduction strategies has become a critical issue for the sustainable development of logistics and transportation. This study focuses on containerized land transportation， aiming to analyze its main emission sources and influencing factors， compare the reduction effects and feasibility of different carbon reduction strategies， and construct a framework for evaluating the effectiveness of greenhouse gas reduction strategies applicable to containerized land transportation. This framework will provide a reference for logistics operators， manufacturers， and government departments in supply chain carbon management and carbon reduction decision-making. Methodology: First， a literature review was conducted to compile major international greenhouse gas quantification standards and transportation emission calculation methods， including IPCC Guidelines， GHG Protocol， GLEC Framework， ISO 14083， and related logistics carbon reduction literature. The emission sources， quantification methods， and carbon reduction strategies for containerized land transportation were summarized. Second， an emission calculation model was established based on activity data， emission coefficients， and Global Warming Potential (GWP). Tank-to-Wheel (TTW) was used as the system boundary， with gCO₂e/ton-km and gCO₂e/TEU-km as functional units to enhance the comparability between different strategies. Simultaneously， Data Quality Indicator (DQI)， sensitivity analysis， and uncertainty analysis were incorporated to verify the robustness and reliability of the model. This study shows that insufficient loading rate， empty vehicle return trips， and vehicle idling are the main factors affecting the emission intensity of containerized land transportation. Among these， operational improvement strategies such as increasing loading rate， reducing empty vehicle rate， route optimization， and Eco-driving have advantages such as lower investment costs， ease of short-term implementation， and significant carbon reduction benefits. In contrast， while technology and system transformation strategies such as electric container trucks， hydrogen-powered vehicles， and multimodal transport have higher long-term carbon reduction potential， they are still limited by factors such as infrastructure construction， energy supply， and investment costs. The analysis results show that increasing loading rate can reduce unit transport emissions by approximately 10% to 30%， reducing empty vehicle rate by approximately 5% to 20%， and route optimization and Eco-driving by approximately 5% to 15%; while strategies such as vehicle electrification and multimodal transport have a long-term carbon reduction potential of 40% to 70% or more. Sensitivity analysis results indicate that load factor， empty vehicle rate， and fuel efficiency are the most important key parameters affecting emissions results， with changes in load factor having the most significant impact on emission intensity. Uncertainty analysis shows that within a reasonable range of activity data variation， the emission quantification model established in this study maintains good robustness， demonstrating the practical application and promotion value of the assessment framework constructed in this study. The main contribution of this study lies in integrating international greenhouse gas quantification standards and logistics transportation management methods to establish a framework for evaluating the effectiveness of carbon reduction strategies applicable to land-based container transportation. This allows for comparison of different carbon reduction measures under consistent functional units， system boundaries， and emission quantification methods. Furthermore， this study further links logistics carbon reduction achievements to corporate Scope 3 supply chain carbon management， strengthening the application value of carbon reduction performance attribution and information disclosure. This can serve as an important reference for logistics companies planning carbon reduction strategies， enterprises promoting supply chain carbon management， and governments formulating low-carbon logistics policies， and can also serve as a foundation for subsequent related research development. Keywords: containerized land transportation， greenhouse gas emissions， carbon reduction strategies， Scope 3， GLEC Framework， ISO 14083， logistics carbon reduction， supply chain carbon management