具耦合電漿子增強之可見光波段電漿子光偵測器;Hot-Electron-Based, Coupled-Plasmon-Enhanced Plasmonic Photodetector at Visible Frequencies

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/82768

Title:	具耦合電漿子增強之可見光波段電漿子光偵測器;Hot-Electron-Based, Coupled-Plasmon-Enhanced Plasmonic Photodetector at Visible Frequencies
Authors:	蕭君育;Hsiao, Chun-Yu
Contributors:	光電科學與工程學系
Keywords:	光偵測器;熱電子;內部光輻射;表面電漿極化子;photodetector;hot-electron;internal photoemission;surface plasmon polaritons
Date:	2020-01-10
Issue Date:	2020-06-05 17:11:33 (UTC+8)
Publisher:	國立中央大學
Abstract:	本研究利用數值模擬、實際製程與量測來設計並且探討具耦合電漿子增強之可見光波段電漿子光偵測器。以橫向磁場極化平面波入射利用粒子群聚演算法優化後所得具特殊旋轉角之二維奈米金屬四角柱光柵之元件結構，中間層鋁的吸收率相當地寬頻，在波長515 nm 至800 nm 超過50%，在波長588 nm 至693 nm 甚至超過60%。另外，此設計的光學特性在可見光波段對於入射光的極化角度不敏感。在和同尺寸之單純「氮化矽-鋁-二氧化鈦-銀」平板結構比較後，可知本研究所設計出之光電轉換元件之所以有高且寬頻的吸收，主要因為二維週期性奈米正四角柱結構產生光柵耦合，可在不同波長時激發中間層鋁上下兩介面之表面電漿子以及特定波長時的間隙電漿共振，導致中間層鋁吸收率增加。在二氧化鈦層中在波長400 nm 附近入射光在該層來回反射的相位差幾近2π，代表平面波在此層產生建設性干涉使得鄰近的中間層鋁吸收率大幅增加。我們將設計出之電漿子光偵測器製作出來並量測於不同之入射光極化角度時之反射率頻譜以及單一極化角度時之電流─電壓圖。由量測結果可得元件對於入射光之極化角度不敏感，此結果與數值模擬相符於波長範圍458.82 nm 至614.55 nm 間，反射率對各極化角度的量測值皆低於20%。電性量測結果最佳之元件在入射光波長為638.9 nm，偏壓-1 V 情況下，光電流為428.7 μA/mm^2，其響應度為301.6 mA/W mm^2，外部量子效率為2.72047%，實驗結果皆遠高於文獻中於同波長下已發表之結果。 ;In this research, we investigate the hot-electron-based, coupled-plasmon-enhanced plasmonic photodetector at visible frequencies numerically and experimentally. The absorptance in mid-Al film of the rotated nano-prisms grating architecture optimized by particle swarm optimization is higher than 50% which begins from the wavelength 515 nm to 800 nm, in addition, the absorptance in mid-metal film is even higher than 60% which begins from the wavelength 588 nm to 693 nm, it is very boardband. Moreover, the optical properties of the photodetector are polarization-independent in the visible region. Compared with the same size of planar structure, the high and boardband absorptance is based on the 2D periodic nano-quadrangular prisms which excite surface plasmon polaritons in the interfaces above and below mid-Al film and excite gap plasmon resonance. The absorptance peak around λ0=400 nm in mid-metal film is caused by constructive interference between the multiple reflections of light between the two reflecting surfaces in titanium dioxide layer. We successfully fabricate the plasmonic photodetector. Later, we measure the reflectance spectrum with mutative polarized plane wave and the current-voltage curve with single polarized plane wave. From the measurement results, we can prove that the reflectance of photodetector is polarization-independent which result is same as simulation. The reflectance is lower than 20% which begins from the wavelength 458.82 nm to 614.55 nm. In the best electrical result of the measurement which is incident by wavelength 638.9 nm source and apply bias voltage -1 V, current under illumination is 428.7 μA/mm^2, responsivity is 301.6 mA/W mm^2$ and EQE is 2.72047$\%$. The measured results are higher than the references which have published in the same wavelength.
Appears in Collections:	[Graduate Institute of Optics and Photonics] Electronic Thesis & Dissertation

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