表面電漿子應用於熱電薄膜之研究

Abstract

本實驗藉由磁控射頻濺鍍製程與熱處理之方法形成不同形貌的金屬奈米銀粒子分布，觀察其微觀結構並直接鍍上一層Bi2Te2.7Se0.3熱電薄膜，量測熱電性質、微觀結構觀察、晶體結構分析等所得之結果，推斷金屬奈米銀粒子結構是否適用於熱電薄膜之熱電效率提升的應用上，研究發現，在奈米銀粒子結構上方覆蓋不同厚度之熱電薄膜層，當熱電薄膜厚度為64 nm，其拉曼光譜具有較明顯的特徵波峰，且金屬銀薄膜的濺鍍時間為10秒鐘，經過真空退火處理使得銀薄膜形成奈米顆粒，退火溫度為400℃，持續30分鐘，此製程參數對熱電薄膜所產生的表面電漿子共振效應最好，另外，我們也將奈米銀粒子生長於熱電薄膜上，由實驗結果得知，奈米銀粒子被包覆於熱電薄膜中，其表面電漿共振強度較大。由於在極接近奈米粒子的表面會引發極強的近場增強型(Near-field Enhancement)電磁場，使得熱電薄膜在金屬奈米粒子的表面電漿子共振效應作用之下，提高其功率因子，實驗得到最佳狀態的表面電漿子共振，最好的熱電功率因子為8.1 W/K2m。

The experiment by sputtering and heat treatment process to form a silver nanoparticles with different morphologies. We observe the thermoelectric properties and microstructure whether the silver nanoparticles can apply to improve the thermoelectric efficiency. As the study found, covering different thickness of thermoelectric thin film layer above the silver nanoparticles, when the thickness of thermoelectric film is 64 nm. The Raman spectroscopy has obvious peaks. And sputtering time of silver film is 10 seconds after vacuum annealing allowing the formation of nanoparticles. The annealing temperature is 400 ℃ and duration time is 30 minutes. As extremely close to the surface of nanoparticles will lead to a highly strong near-field enhanced electromagnetic fields, making the thermoelectric film under the plasmson resonance effect improve its power factor. The best thermoelectric power factor is 8.1 W/K2m.