Wen, Yu-Chieh / Assistant Research Fellow

Research Interest

• Surface physical chemistry, Ultrafast spectroscopy for quantum materials, Nonlinear optics, Laser spectroscopy

Experience

• Postdoc, Dept. of Physics, University of California, Berkeley
• Postdoc, Dept. of Physics, Fudan University, China
• Postdoc, Inst. of Physics, Academia Sinica

Publication

Journal Papers

• [1]     L. Dalstein, K.-Y. Chiang, and Y.-C. Wen*, 2023, “Surface Potential at Electrolyte/Air Interfaces: A Quantitative Analysis via Sum-Frequency Vibrational Spectroscopy”, JOURNAL OF PHYSICAL CHEMISTRY B, 127 (21), 4915-4921. (SCIE) (IF: 2.991; SCI ranking: 57.4%)
  
  
• [2]     Yao Hsiao, Ting-Han Chou, Animesh Patra, and Yu-Chieh Wen*, 2023, “Momentum-dependent sum-frequency vibrational spectroscopy of bonded interface layer at charged water interfaces”, SCIENCE ADVANCES, 9, eadg2823. (SCIE) (IF: 14.143; SCI ranking: 6.8%)
  
  
• [3]     L. Dalstein, J.-R. Huang, and Y.-C. Wen*, 2020, “Wavelength-Scanning Second Harmonic Generation for Determining Absolute Charge Density at Aqueous Interfaces”, OPTICS LETTERS, 45(13), 3733. (SCIE) (IF: 3.776; SCI ranking: 22.2%)
  
  
• [4]     K.-Y. Chiang, L. Dalstein, and Y.-C. Wen*, 2020, “Affinity of Hydrated Protons at Intrinsic Water/Vapor Interface Revealed by Ion-Induced Water Alignment”, JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 11, 696. (SCIE) (IF: 6.475; SCI ranking: 23.5%,23.5%,32.7%,8.1%)
  
  
• [5]     L. Dalstein, K.-Y. Chiang, and Y.-C. Wen*, 2019, “Direct Quantification of Water Surface Charge by Phase-Sensitive Second Harmonic Spectroscopy”, JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 10, 5200−5205. (SCIE) (IF: 6.475; SCI ranking: 23.5%,23.5%,32.7%,8.1%)
  
  
• [6]     X. Liu, G. Huang, K.-K. Hu, N. Sheng, C. Tian, Y. R. Shen, Y.-C. Wen, G. Shi*, and H. Fang, 2018, “Sharing of Na+ by Three -COO- Groups at Deprotonated Carboxyl-Terminated Self-Assembled Monolayers Charged Aqueous Interface”, JOURNAL OF PHYSICAL CHEMISTRY C, 122, 9111. (SCIE) (IF: 4.126; SCI ranking: 42%,36.9%,52.3%)
  
  
• [7]     Y.-C. Wen, S. Zha, C. Tian*, and Y. R. Shen*, 2016, “Surface pH and Ion Affinity at the Alcohol-Monolayer/Water Interface Studied by Sum-Frequency Spectroscopy”, Journal of Physical Chemistry C, 120, 15224. (SCIE) (IF: 4.126; SCI ranking: 42%,36.9%,52.3%)
  
  
• [8]     K.-H. Lin*, K.-J. Wang, C.-C. Chang, Y.-C. Wen, B. Lv, C.-W. Chu, and M.-K. Wu*, 2016, “Ultrafast Dynamics of Quasiparticles and Coherent Acoustic Phonons in Slightly Underdoped (BaK)Fe2As2”, Scientific Reports, 6, 25962. (SCIE) (IF: 4.38; SCI ranking: 23.3%)
  
  
• [9]     Y.-C. Wen, S. Zha, X. Liu, S. Yang, P. Guo, G. Shi, H. Fang, Y. R. Shen*, and C. Tian*, 2016, “Unveiling Microscopic Structures of Charged Water Interfaces by Surface-Specific Vibrational Spectroscopy”, PHYSICAL REVIEW LETTERS, 116, 016101. (SCIE) (IF: 9.161; SCI ranking: 8.1%)
  
  
• [10]     M.-K. Wu*, P. Wu, Y.-C. Wen, M.-J. Wang, P.-H. Lin, W.-C. Lee, T.-K. Chen, and C.-C. Chang, 2015, “An Overview of the Fe-Chalcogenide Superconductors”, JOURNAL OF PHYSICS D-APPLIED PHYSICS, 48, 323001. (SCIE) (IF: 3.207; SCI ranking: 36.3%)
  
  
• [11]     C.-C. Chang, T.-K. Chen, W.-C. Lee, P.-H. Lin, M.-J. Wang, Y.-C. Wen, P.-M. Wu, and M.-K. Wu*, 2015, “Superconductivity in Fe-chalcogenides”, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 514, 423. (SCIE) (IF: 1.241; SCI ranking: 83.8%,82.6%)
  
  
• [12]     K.-H. Lin*, K.-J. Wang, C.-C. Chang, Y.-C. Wen, D.-H. Tsai, Y.-R. Wu, Y.-T. Hsieh, M.-J. Wang, B. Lv, P. C.-W. Chu, and M.-K. Wu*, 2014, “Observation of Pseudogaplike Feature above Tc in LiFeAs by Ultrafast Optical Spectroscopy”, PHYSICAL REVIEW B, 90, 174502. (SCIE) (IF: 4.036; SCI ranking: 38.7%,25.6%,31.9%)
  
  
• [13]     P.-A. Mante, C.-C. Chen, Y.-C. Wen, H.-Y. Chen, S.-C. Yang, Y.-R. Huang, I.-J. Chen, Y.-W. Chen, V. Gusev, M.-J. Chen, J.-L. Kuo, J.-K. Sheu, and C.-K. Sun*, 2014, “Probing Hydrophilic Interface of Solid/Liquid-Water by Nanoultrasonics”, Scientific Reports, 4, 6249. (SCIE) (IF: 4.38; SCI ranking: 23.3%)
  
  
• [14]     P.-A. Mante, C.-C. Chen, Y.-C. Wen, J.-K. Sheu, and C.-K. Sun*, 2013, “Thermal Boundary Resistance between GaN and Cubic Ice and THz Acoustic Attenuation Spectrum of Cubic Ice from Complex Acoustic Impedance Measurements”, PHYSICAL REVIEW LETTERS, 111, 225901. (SCIE) (IF: 9.161; SCI ranking: 8.1%)
  
  
• [15]     C.-W. Luo*, I.-H. Wu, P.-C. Cheng, J.-Y. Lin, K.-H. Wu, T.-M. Uen, J.-Y. Juang, T. Kobayashi, Y.-C. Wen, T.-W Huang, K.-W. Yeh, M.-K. Wu., D. A. Chareev, O. S. Volkova, and A. N. Vasiliev, 2012, “Ultrafast Dynamics and Phonon Softening in Fe1+ySe1−xTex Single Crystals”, NEW JOURNAL OF PHYSICS, 14, 103053. (SCIE) (IF: 3.732; SCI ranking: 25.6%)
  
  
• [16]     P.-A. Mante, H.-Y. Chen, M.-H. Lin, Y.-C. Wen, S. Gwo, and C.-K. Sun*, 2012, “Selectively Probing Vibrations in A Plasmonic Supracrystal”, APPLIED PHYSICS LETTERS, 101, 101903. (SCIE) (IF: 3.791; SCI ranking: 29.4%)
  
  
• [17]     Y.-C. Wen, K.-J. Wang, H.-H. Chang, J.-Y. Luo, C.-C. Shen, H.-L. Liu, C.-K. Sun, M.-J. Wang, and M.-K. Wu*, 2012, “Gap Opening and Orbital Modification of Superconducting FeSe above the Structural Distortion”, PHYSICAL REVIEW LETTERS, 108, 267002. (SCIE) (IF: 9.161; SCI ranking: 8.1%)
  
  
• [18]     A. Devos*, Y.-C. Wen, P.-A. Mante, and C.-K. Sun, 2012, “Comment to “Obsercation of Anomalous Acoustic Phonon Dispersion in SrTiO3 by Broadband Stimulated Brillouin Scattering”, APPLIED PHYSICS LETTERS, 100, 206101. (SCIE) (IF: 3.791; SCI ranking: 29.4%)
  
  
• [19]     Y.-C. Wen, G.-W. Chern, K.-H. Lin, J. J. Yeh, and C.-K. Sun*, 2011, “Femtosecond Optical Excitation of Coherent Acoustic Phonons in a Piezoelectric p-n Junction”, PHYSICAL REVIEW B, 84, 205315. (SCIE) (IF: 4.036; SCI ranking: 38.7%,25.6%,31.9%)
  
  
• [20]     Y.-C. Wen, Y.-C. Liao, H.-H. Chang, B.-H. Mok, T.-W. Huang, K.-W. Yeh, J.-Y. Luo, M.-J. Wang, C.-K. Sun, and M.-K. Wu*, 2011, “Elastic Stiffness of Single-Crystalline FeSe Measured by Picosecond Ultrasonics”, JOURNAL OF APPLIED PHYSICS, 110, 073505. (SCIE) (IF: 2.546; SCI ranking: 49.4%)
  
  
• [21]     Y.-C. Wen, S.-H. Guol, H.-P. Chen, J.-K. Sheu, and C.-K. Sun*, 2011, “Femtosecond Ultrasonic Spectroscopy Using A Piezoelectric Nanolayer: Hypersound Attenuation in Vitreous Silica Films”, APPLIED PHYSICS LETTERS, 99, 051913. (SCIE) (IF: 3.791; SCI ranking: 29.4%)
  
  
• [22]     Y.-E. Su, Y.-C. Wen, Y.-L. Hong, H.-M. Lee, S. Gwo, Y.-T. Lin, L.-W. Tu, H.-L. Liu, and C.-K. Sun*, 2011, “Using Hole Screening Effet on Hole-Phonon Interaction to Estimate Hole Density in Mg-doped InN”, APPLIED PHYSICS LETTERS, 98, 252106. (SCIE) (IF: 3.791; SCI ranking: 29.4%)
  
  
• [23]     Y.-H. Chen, Y.-C. Wen, W.-R. Liu, W.-F. Hsieh, and C.-K. Sun*, 2011, “Acoustic Velocity and Optical Index Birefringence in A-Plane ZnO Thin Films”, CHINESE JOURNAL OF PHYSICS, 49, 201. (SCIE) (IF: 3.237; SCI ranking: 33.7%)
  
  
• [24]     Y.-C. Wen, J.-H. Sun, T.-T. Wu, C. Dais, D. Grützmacher, and C.-K. Sun*, 2011, “Investigations of Phononic Bandgap in A 3D Quantum-Dot Crystal”, CHINESE JOURNAL OF PHYSICS, 49, 77. (SCIE) (IF: 3.237; SCI ranking: 33.7%)
  
  
• [25]     H.-P. Chen, Y.-C. Wen, Y.-H. Chen, C.-H. Tsai, K.-L. Lee, P.-K. Wei, J.-K. Sheu, and C.-K. Sun*, 2010, “Femtosecond Laser-Ultrasonic Investigation of Plasmonic Fields on The Metal/Gallium Nitride Interface”, APPLIED PHYSICS LETTERS, 97, 201102. (SCIE) (IF: 3.791; SCI ranking: 29.4%)
  
  
• [26]     Y.-C. Wen, J.-H. Sun, C. Dais, D. Grützmacher, T.-T. Wu, J.-W. Shi, and C.-K. Sun*, 2010, “Three-Dimensional Phononic Nanocrystal Composed of Ordered Quantum Dots”, APPLIED PHYSICS LETTERS, 96, 123113. (SCIE) (IF: 3.791; SCI ranking: 29.4%)
  
  
• [27]     Y.-E. Su, Y.-C. Wen, H.-M. Lee, S. Gwo, and C.-K. Sun*, 2010, “Observation of Sub-100 Femtosecond Electron Cooling Time in InN”, APPLIED PHYSICS LETTERS, 96, 052108. (SCIE) (IF: 3.791; SCI ranking: 29.4%)
  
  
• [28]     Y.-C. Wen, C.-L. Hsieh, K.-H. Lin, H.-P. Chen, S.-C. Chin, C.-L. Hsiao, Y.-T. Lin, C.-S. Chang, Y.-C. Chang, L.-W. Tu, and C.-K. Sun*, 2009, “Specular Scattering Probability of Acoustic Phonons in Atomically Flat Interfaces”, PHYSICAL REVIEW LETTERS, 103, 264301. (SCIE) (IF: 9.161; SCI ranking: 8.1%)
  
  
• [29]     Y.-C. Wen, T.-S. Ko, T.-C. Lu, H.-C. Kuo, J.-I. Chyi, and C.-K. Sun*, 2009, “Photogeneration of Coherent Shear Phonons in Oriented Wurtzite Semiconductors by Piezoelectric Coupling”, PHYSICAL REVIEW B, 80, 195201. (SCIE) (IF: 4.036; SCI ranking: 38.7%,25.6%,31.9%)
  
  
• [30]     P.-H. Wang, Y.-C. Wen, S.-H. Guol, C.-M. Lai, H.-C. Lin, P.-R. Chen, J.-W. Shi, J.-I. Chyi, and C.-K. Sun*, 2009, “Electrically Manipulating the Optical Sensitivity Function in Quantum-Wells for Nanoacoustic Wave Detection”, APPLIED PHYSICS LETTERS, 95, 143108. (SCIE) (IF: 3.791; SCI ranking: 29.4%)
  
  
• [31]     S.-Z. Sun, Y.-C. Wen, S.-H. Guol, H.-M. Lee, S. Gwo, and C.-K. Sun*, 2008, “Observation of Femtosecond Carrier Thermalization Time in Indium Nitride”, JOURNAL OF APPLIED PHYSICS, 103, 123513. (SCIE) (IF: 2.546; SCI ranking: 49.4%)
  
  
• [32]     M.-C. Chan, S.-W. Chu, C.-H. Tseng, Y.-C. Wen, Y.-H. Chen, G.-D. John Su, and C.-K. Sun*, 2008, “Cr:Forsterite-Laser-Based Fiber-Optic Nonlinear Endoscope with Higher Efficiencies”, MICROSCOPY RESEARCH AND TECHNIQUE, 71, 559. (SCIE) (IF: 2.769; SCI ranking: 19%,39.8%,33.3%)
  
  
• [33]     S.-P. Tai, Y. Wu, D.-B. Shieh, L.-J. Chen, K.-J. Lin, C.-H. Yu, S.-W. Chu, C.-H. Chang, X.-Y. Shi, Y.-C. Wen, K.-H. Lin, T.-M. Liu, and C.-K. Sun*, 2007, “Molecular Imaging of Cancer Cells Using Plasmon-resonant-enhanced Third-harmonic-generation in Silver Nanoparticles”, ADVANCED MATERIALS, 19, 4520. (SCIE) (IF: 30.849; SCI ranking: 2.8%,2.5%,2.7%,2.8%,3.1%,2.9%)
  
  
• [34]     C.-Y. Chen, Y.-C. Wen, H.-P. Chen, T.-M. Liu, C.-C. Pan, J.-I. Chyi, and C.-K. Sun*, 2007, “Narrow Band Detection of Propagating Coherent Acoustic Phonons in Piezoelectric InGaN/GaN Multiple-quantum Wells”, APPLIED PHYSICS LETTERS, 91, 133101. (SCIE) (IF: 3.791; SCI ranking: 29.4%)
  
  
• [35]     Y.-C. Wen, L.-C. Chou, H.-H. Lin, V. Gusev, K.-H. Lin, and C.-K. Sun*, 2007, “Efficient Generation of Coherent Acoustic Phonons in (111) InGaAs/GaAs Multiple Quantum Wells through Piezoelectric Effects”, APPLIED PHYSICS LETTERS, 90, 172102. (SCIE) (IF: 3.791; SCI ranking: 29.4%)
  
  
• [36]     Y.-C. Wen, C.-Y. Chen, C.-H. Shen, S. Gwo, and C.-K. Sun*, 2006, “Ultrafast Carrier Thermalization in InN”, APPLIED PHYSICS LETTERS, 89, 232114. (SCIE) (IF: 3.791; SCI ranking: 29.4%)
  
  
• [37]     Y.-C. Wen, L.-C. Chou, H.-H. Lin, K.-H. Lin, T.-F. Kao, and C.-K. Sun*, 2006, “Compositional Dependence of Longitudinal Sound Velocities of Piezoelectric (111) InxGa(1-x)As Measured by Picosecond Ultrasonics”, JOURNAL OF APPLIED PHYSICS, 100, 103516. (SCIE) (IF: 2.546; SCI ranking: 49.4%)
  
  
• [38]     T.-M. Liu, S.-P. Tai, C.-H. Yu, Y.-C. Wen, S.-W. Chu, L.-J. Chen, M. Prasad, K.-J. Lin, and C.-K. Sun*, 2006, “Measuring Plasmon-resonance Enhanced Third-harmonic chi(3) of Ag Nanoparticles”, APPLIED PHYSICS LETTERS, 89, 043122. (SCIE) (IF: 3.791; SCI ranking: 29.4%)
  
  
• [39]     K.-H. Lin, C.-T. Yu, Y.-C. Wen, C.-K. Sun*, 2005, “Generation of Picosecond Acoustic Pulses Using a P-N Junction with Piezoelectric Effects”, APPLIED PHYSICS LETTERS, 86, 093110. (SCIE) (IF: 3.791; SCI ranking: 29.4%)
  
  

Chapters in Books

• [1]     Y.-C. Wen, T.-M. Liu, C. Dais, D. Grützmacher, T.-T. Chen, Y.-F. Chen, J.-W. Shi, and C.-K. Sun, 2010, “Bandgap Characteristics of A 3D Phononic Metamaterial composed of Ordered Quantum Dots”, editor(s): Tsung-Tsong Wu and Chien-Ching Ma, IUTAM Symposium on Recent Advances of Acoustic Waves in Solids (IUTAM Bookseries, Vol. 26), pp. 201-208, Berlin, Germany: Springer.
  
  

發現與突破

• [1]     西元年：2023
  研究人員(中)：溫昱傑、蕭堯、周廷翰、Animesh Patra
  研究人員(英)：WEN, YU-CHIEH, Y. Hsiao, T.-H. Chou, A. Patra
  研究成果名稱(中)：利用動量解析式光學和頻振動光譜探測帶電水界面的鍵結界面層
  研究成果名稱(英)：Momentum-Dependent Sum-Frequency Vibrational Spectroscopy of Bonded Interface Layer at Charged Water Interfaces
  簡要記述(中)：帶電水界面主導許多自然現象，並對於先進觸媒和能源儲存裝置的發展非常重要。其中微觀界面的過程，例如離子脫溶和反應中的電荷轉移，直接受水界面特異性的氫鍵網絡控制。然而，人們對這些鍵結水層結構以及其中離子和分子之間的相互作用的知識非常有限。本所溫昱傑博士團隊開發出一種動量解析式非線性光學技術，可用於量測界面鍵結水層及離子擴散層的振動光譜，從而獲得有關水界面微觀結構和帶電狀態等微觀訊息。此團隊利用模型表面活性劑與水的界面展示出新技術的突破性。實驗結果揭露了一個隱藏、具有弱氫鍵供體的水分子鍵結狀態，暗示表面活性劑頭基具有完整但非對稱的水合層結構。在另一個應用中，研究團隊在兩性離子磷脂酰膽鹼脂質(zwitterionic phosphatidylcholine lipid) 與水的界面，發現了受脂質頭基影響而高度極化的鍵結水層結構。本研究提供了一種在分子層級、原位探測電化學與生物/水溶液界面的可行方法，其並進一步強調了應用動量解析非線性光學於探索具體背景訊號情況下的表面激發，從而擴展了表面非線性光學在一般凝態物理研究中的應用。
  簡要記述(英)：Charged water interfaces are responsible for many natural phenomena and of great importance in the development of advanced catalysts and energy storage devices. Microscopic interfacial processes, such as ion desolvation and charge transfer in reactions, are directly controlled by the interface-specific hydrogen-bonding network of water. However, knowledge on these bonded water layer structures and the interplay between ionic and molecular species therein is very limited. A research team led by Dr. Yu-Chieh Wen at Institute of Physics (IoP) now develop a nonlinear optical spectroscopic scheme with varying photon momenta for retrieving the vibrational spectra of the bonded interface water layer and the ion diffuse layer and, hence, microscopic structural and charging information about aqueous interfaces. Using a model surfactant-water interface as a demonstration, the result revealed a hidden weakly donor hydrogen-bonded water species, suggesting an asymmetric hydration-shell structure of fully solvated surfactant headgroups. In another application to a zwitterionic phosphatidylcholine lipid monolayer–water interface, the team found a highly polarized bonded water layer structure associating to the phosphatidylcholine headgroup. This all-optic method offers an in situ microscopic probe of electrochemical and biological interfaces. The study further highlights the opportunities of applying momentum-resolved nonlinear optics to explore surface excitations in bulk backgrounds, which broadens the application of surface nonlinear optics to general condensed matter research.
  

  主要相關著作：

  Yao Hsiao, Ting-Han Chou, Animesh Patra, and Yu-Chieh Wen*, 2023, “Momentum-dependent sum-frequency vibrational spectroscopy of bonded interface layer at charged water interfaces”, SCIENCE ADVANCES, 9, eadg2823. (SCIE) (IF: 14.143; SCI ranking: 6.8%)

  
  
  
• [2]     西元年：2020
  研究人員(中)：溫昱傑、江國揚, 拉提雅
  研究人員(英)：WEN, YU-CHIEH, K.-Y. Chiang and L. Dalstein
  研究成果名稱(中)：由水分子排列結構分析水合質子在水與空氣界面的吸附能
  研究成果名稱(英)：Affinity of hydrated proton at intrinsic water/vapor interface revealed by ion-induced water alignment
  簡要記述(中)：本研究著重於理解在水與空氣介面的質子吸附行為。這樣的過程在大氣化學和環境科學中扮演重要腳色，並可視為了解氫鍵分子系統中核量子效應的一個模型系統。儘管其重要性，質子吸附到水-空氣界面的定量表徵長期以來一直是實驗和理論上的挑戰。我們的工作正是研究方向上的突破。我們利用相位靈敏式和頻振動光譜研究水表面電場所誘導的分子排列，藉此分析出水-空氣界面的表面電荷及質子密度。我們並發現質子的界面吸附與其和簡單陰離子(如鹵素）的交互作用無關，並其依循恆定的吸附自由能–3.74（±0.56）kJ / mol。這是人類第一次微觀尺度下，通過分子光譜直接測量水合質子對水與空氣界面的吸附能。我們的發現不僅能為重要大氣過程提供更進一步的理解，並為在氫鍵分子系統中進行核量子效應模擬提供了微觀層面的基礎。也解決了長期關於水表面酸鹼度的爭議。
  簡要記述(英)：Our work focuses on adsorption of protons to the air/water interface. Such a process plays a vital role in atmospheric chemistry and environmental science, and serve as a model system for exploring nuclear quantum effects in surfaces of hydrogen-bonded systems. Despite its importance, quantitative characterization of the proton adsorption to the intrinsic water/vapor interface has long been an experimental and theoretical challenge. Our work is a breakthrough in this direction.We report in this paper a phase-sensitive sum-frequency vibrational spectroscopic (PS-SFVS) study on quantification of the surface density of protons (or their hydronium form) at the water/vapor interface, through inspecting the surface-field-induced alignment of water molecules in the electrical double layer of ions. With hydrogen halides in water, the surface adsorption of protons is found to be independent of specific proton-halide anion interactions and to follow a constant adsorption free energy, –3.74 (±0.56) kJ/mol, for bulk ion concentrations up to 0.3 M. This is the first time the proton affinity to an intrinsic water/vapor interface has ever been directly measured through a molecular-level spectroscopy (without extrinsic label molecules, e.g., dye, nor crucial model assumption used in interpreting macroscopic observables, e.g., surface tension and electrokinetic mobility). Our findings are not only of importance for better understanding of relevant atmospheric processes, but also offer a microscopic-level basis to develop advanced quantum-mechanical models for molecular simulations of nuclear quantum effects in hydrogen-bonded systems, and to address the long-standing debate regarding acidity of the water surface.
  

  主要相關著作：

  K.-Y. Chiang, L. Dalstein, and Y.-C. Wen*, 2020, “Affinity of Hydrated Protons at Intrinsic Water/Vapor Interface Revealed by Ion-Induced Water Alignment”, JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 11, 696. (SCIE) (IF: 6.475; SCI ranking: 23.5%,23.5%,32.7%,8.1%)

  
  
  
• [3]     西元年：2019
  研究人員(中)：溫昱傑、拉提雅, 江國揚
  研究人員(英)：WEN, YU-CHIEH, L. Dalstein and K.-Y. Chiang
  研究成果名稱(中)：利用相位靈敏式二倍頻光譜技術直接定量水溶液表面電荷
  研究成果名稱(英)：Direct Quantification of Water Surface Charge by Phase-Sensitive Second Harmonic Spectroscopy
  簡要記述(中)：帶電荷的水介面主導許多自然現象，也在現今能源轉換或能源儲存元件中扮演重要角色。人們對於帶電水介面的物理模型一般基於一個電雙層結構，其中表面電荷控制介面反應的微觀路徑，因此影響水溶液介面系統的化學、生物性質與功能性。雖然現今已有許多方法可估計水溶液表面電荷，但大多需仰賴熱動力學模型與假設以進行分析，這導致分析結果常具有爭議。本研究工作發展一套相位靈敏式光學二倍頻光譜技術，其可在不進行熱動力學模型、或電雙層結構模型情況下，對水溶液界面電荷進行直接量測。我們不僅證明此新方法的原理，成功展示其應用。並且對於其使用限制提供完整的評估。
  簡要記述(英)：Our work focuses on characterization of the electrical double layer (EDL) at water interfaces. Such an interfacial charged layer is an essential ingredient for diverse biological and chemical processes and responsible for many modern technologies such as photocatalysis for water splitting and proton-exchange membrane fuel cells. Despite its importance, quantitative characterization of an EDL without crucial model assumption has long been a challenge. Our work is a breakthrough in this direction.
  We report in this paper a new phase-sensitive second-harmonic-generation (SHG) spectroscopic scheme that allows direct quantification of the surface charge density and surface potential of an EDL for any planar aqueous interface accessible by light, without need of prior interfacial information. This method relies on selective probing of the surface-field-induced reorientation order of water molecules in the EDL (associated with the third-order nonlinear susceptibility of bulk water) and is, hence, independent of the microscopic interfacial structure. For demonstration, we examine a mixed organic-molecule monolayer on water as an example. The surface charge density obtained from our method reveals the manifest effect of the chain-chain interactions between heterogeneous molecules among the monolayer on adsorption of soluble ionic surfactants. This is the first time the surface charge density at heterogeneous organic monolayers on water has ever been directly measured without (thermodynamic, chemical, or electrokinetic) assumption nor isotope replacement.
  

  主要相關著作：

  L. Dalstein, K.-Y. Chiang, and Y.-C. Wen*, 2019, “Direct Quantification of Water Surface Charge by Phase-Sensitive Second Harmonic Spectroscopy”, JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 10, 5200−5205. (SCIE) (IF: 6.475; SCI ranking: 23.5%,23.5%,32.7%,8.1%)