本論文設計並實作了基於塔姆電漿共振 (Tamm Plasmon Resonance, TPR) 之二維材料二硫化鉬 (MoS2) 熱載子光偵測器。過渡金屬硫族化合物如單層 MoS2，因具備原子級厚度與優異的載子遷移率，在光電元件領域備受矚目。而單層 MoS2 的本徵能隙約為 1.8 eV，其光學吸收邊界限制在 680 nm 以下，這導致材料先天無法對紅外光譜區產生吸收響應。為突破此一物理能隙限制，本研究利用金屬薄膜激發表面電漿子，並透過朗道阻尼的非輻射衰減產生高動能熱載子，進而利用跨越蕭特基能障 (Schottky barrier) 的內部光電效應 (Internal Photoemission, IPE) 實現紅外光偵測。
在元件製備與製程方面，本研究選用化學氣相沉積法 (CVD) 成長的單層 MoS2 作為主要的半導體通道材料，並針對近紅外光 (808 nm) 與短波紅外通訊波段 (1550 nm) 兩個目標波段進行調控。為了釐清熱載子的微觀傳輸機制，本研究設計了兩款不同的幾何光罩圖形，透過系統性地改變金屬反射鏡面積大小以及金屬與 MoS2 的幾何重疊比例，確立熱載子的收集條件。
實驗結果顯示，在光學特性分析中，利用垂直入射反射光譜證實兩組元件結構皆成功激發了塔姆電漿共振模態，並透過不同入射角下的反射光譜驗證了共振吸收峰隨入射角增加而藍移的特性，提供了共振波長的調控彈性。在電性與光響應量測中，當使用能量低於材料能隙的 808 nm 與 1550 nm 雷射進行週期性照射時，元件均展現了與光照同步的開關響應，直接證實此結構能有效突破傳統半導體的吸收極限。
透過不同幾何設計的數據對照，本研究揭示了熱載子的傳輸極限。金屬面積較大者的光響應度明顯不如面積較小者，證實熱載子在金屬內部的非彈性平均自由徑 (IMFP) 極短，遠距離生成的熱電子會在晶格傳輸中因頻繁散射而發生熱化損耗。而當採取材料與金屬完全重疊的夾層設計 (Au / MoS2 / DBR) 以縮短金屬端傳輸距離時，光電流顯著提升。兩個不同波段元件的最佳內部量子效率 (IQE) 均落在相同的數量級，在初始動能相差甚遠的條件下表現相近，有力地驗證了 TPR 架構能有效局域化光場並降低熱載子傳輸的能量衰減。

Two-dimensional molybdenum disulfide (MoS2) has garnered significant attention in optoelectronics due to its atomic-scale thickness, good surface stability, and excellent optoelectronic properties. However, the intrinsic direct bandgap of monolayer MoS2 is approximately 1.8 eV, which primarily restricts its photoresponse to the visible-light spectrum. Consequently, its direct application in near-infrared (NIR) and short-wave infrared (SWIR) photodetection, such as the 808 nm and 1550 nm wavelength bands, is severely limited.
This study proposes a novel hot-carrier photodetector architecture designed to overcome this fundamental bandgap limitation by integrating Tamm plasmon resonance (TPR) with a MoS2 metal-semiconductor junction. The device employs a vertical stacking structure consisting of Au/MoS2/DBR (distributed Bragg reflector). In this configuration, incident light induces a highly localized optical field at the interface between the top gold (Au) metal layer and the underlying DBR, generating high-energy hot carriers within the metal. Driven by the internal photoemission (IPE) mechanism, these hot carriers acquire sufficient energy to cross the Schottky barrier at the Au/MoS2 interface and are subsequently injected into the MoS2 transport channel to generate a measurable photocurrent.
To validate this approach, two sets of Tamm plasmon polariton (TPP) photodetectors were systematically designed and fabricated, targeting the 808 nm and 1550 nm wavelength bands. The 808 nm device utilizes an SiO2/Si3N4 DBR structure, while the 1550 nm device employs a Ta2O5/SiO2 DBR structure to achieve the desired resonance wavelengths. Reflection spectroscopy confirmed the successful formation of distinct TPP absorption peaks near the target wavelengths, which exhibited a blueshift with increasing incident angles, perfectly aligning with the simulation results. Furthermore, optoelectronic measurements demonstrated that both devices exhibited stable photo-switching responses under 808 nm and 1550 nm laser illumination, despite the photon energies being considerably lower than the MoS2 bandgap.
This study also conducted a comprehensive investigation into the hot-carrier transport and collection mechanisms by varying the geometrical design, specifically the Au metal area and the overlap ratio between the MoS2 channel and the Au metal reflector. The experimental results demonstrated that simply enlarging the metal absorption area does not proportionally enhance the photoresponse, as the effective transport distance of hot carriers within the metal is heavily constrained by scattering mechanisms. Conversely, maximizing the geometric overlap between the MoS2 channel and the Au/DBR resonance region effectively shortens the hot-carrier transport distance, leading to significantly enhanced photocurrent collection.
In conclusion, this research successfully establishes a wavelength-tunable, planarized infrared photodetector platform capable of seamless integration with two-dimensional materials. This architecture presents a highly feasible and promising direction for the future development of low-cost, narrowband, and tunable infrared photodetection systems based on two-dimensional semiconductors.

[1] B. Oksengendler and N. Turaeva, "Surface tamm states at curved surfaces of ionic crystals," in Doklady Physics, 2010, vol. 55, no. 10.
[2] A. Kavokin, I. Shelykh, and G. Malpuech, "Optical Tamm states for the fabrication of polariton lasers," Applied Physics Letters, vol. 87, no. 26, 2005.
[3] M. Kaliteevski et al., "Tamm plasmon-polaritons: Possible electromagnetic states at the interface of a metal and a dielectric Bragg mirror," Physical Review B—Condensed Matter and Materials Physics, vol. 76, no. 16, p. 165415, 2007.
[4] M. Sasin et al., "Tamm plasmon polaritons: Slow and spatially compact light," Applied physics letters, vol. 92, no. 25, 2008.
[5] C. Zhang, K. Wu, V. Giannini, and X. Li, "Planar hot-electron photodetection with Tamm plasmons," ACS nano, vol. 11, no. 2, pp. 1719–1727, 2017.
[6] Q. H. Wang, K. Kalantar-Zadeh, A. Kis, J. N. Coleman, and M. S. Strano, "Electronics and optoelectronics of two-dimensional transition metal dichalcogenides," Nature nanotechnology, vol. 7, no. 11, pp. 699–712, 2012.
[7] P.-C. Shen et al., "Ultralow contact resistance between semimetal and monolayer semiconductors," Nature, vol. 593, no. 7858, pp. 211–217, 2021.
[8] J. D. Joannopoulos, P. R. Villeneuve, and S. Fan, "Photonic crystals," Solid State Communications, vol. 102, no. 2-3, pp. 165–173, 1997.
[9] S. Robinson and R. Nakkeeran, "Photonic crystal ring resonator based optical filters," Advances in Photonic Crystals, vol. 1, pp. 1–26, 2013.
[10] C. Zhang, R. ElAfandy, and J. Han, "Distributed Bragg reflectors for GaN-based vertical-cavity surface-emitting lasers," Applied Sciences, vol. 9, no. 8, p. 1593, 2019.
[11] 李正中, "薄膜光學與鍍膜技術," 藝軒圖書出版社, pp. 559–583, 2020.
[12] J. Zhang, L. Zhang, and W. Xu, "Surface plasmon polaritons: physics and applications," Journal of Physics D: Applied Physics, vol. 45, no. 11, p. 113001, 2012.
[13] H. H. Nguyen, J. Park, S. Kang, and M. Kim, "Surface plasmon resonance: a versatile technique for biosensor applications," Sensors, vol. 15, no. 5, pp. 10481–10510, 2015.
[14] S. Unser, I. Bruzas, J. He, and L. Sagle, "Localized surface plasmon resonance biosensing: current challenges and approaches," Sensors, vol. 15, no. 7, pp. 15684–15716, 2015.
[15] H. Zhou, G. Yang, K. Wang, H. Long, and P. Lu, "Multiple optical Tamm states at a metal–dielectric mirror interface," Optics Letters, vol. 35, no. 24, pp. 4112–4114, 2010.
[16] J. Wang et al., "Broadband Tamm plasmon-enhanced planar hot-electron photodetector," Nanoscale, vol. 12, no. 47, pp. 23945–23952, 2020.
[17] C. Clavero, "Plasmon-induced hot-electron generation at nanoparticle/metal-oxide interfaces for photovoltaic and photocatalytic devices," Nature Photonics, vol. 8, no. 2, pp. 95–103, 2014.
[18] M. L. Brongersma, N. J. Halas, and P. Nordlander, "Plasmon-induced hot carrier science and technology," Nature nanotechnology, vol. 10, no. 1, pp. 25–34, 2015.
[19] 詩敏、李明逵, 半導體元件物理與製作技術. 國立陽明交通大學出版社, 2013, pp. 460–461.
[20] D. A. Neamen and D. Biswas, Semiconductor physics and devices. McGraw-Hill higher education New York, 2011.
[21] 詩敏、李明逵, 半導體元件物理與製作技術. 國立陽明交通大學出版社, 2013.
[22] S. Sze and K. K. Ng, "LEDs and lasers," Physics of semiconductor devices, vol. 3, pp. 663–742, 2006.
[23] M. R. Islam et al., "Tuning the electrical property via defect engineering of single layer MoS 2 by oxygen plasma," Nanoscale, vol. 6, no. 17, pp. 10033–10039, 2014.
[24] M. Ohring, Materials science of thin films: depositon and structure. Academic press, 2002.
[25] C. Lee, H. Yan, L. E. Brus, T. F. Heinz, J. Hone, and S. Ryu, "Anomalous lattice vibrations of single-and few-layer MoS2," ACS nano, vol. 4, no. 5, pp. 2695–2700, 2010.
[26] M. Kadleıková, J. Breza, and M. Veselý, "Raman spectra of synthetic sapphire," Microelectronics journal, vol. 32, no. 12, pp. 955–958, 2001.
[27] M. Electric. "ML9xx45 Series 1550, 1520nm InGaAsP FP Laser Diodes," Data sheet. [Online] Available: https://www.alldatasheet.com/datasheet-pdf/download/197001/MITSUBISHI/ML925B45F.html