在本研究中，我們報導一種透過聚苯乙烯奈米球微影術結合金屬輔助催化蝕刻法的新穎製程，成功地在(001)矽單晶基材製備出大面積規則準直排列之矽晶奈米管陣列結構，並藉由調控聚苯乙烯奈米球之尺寸與濕式蝕刻時間可以分別控制矽單晶奈米管的內外徑以及長度。由SEM、TEM影像圖及相對應之電子選區繞射圖譜鑑定分析可得知所製備出之矽晶奈米管具有高度準直性且為單晶結構。在波長範圍400-1600 nm的光譜量測結果顯示，因矽晶奈米管可視為是由奈米柱與奈米洞共同組成之複合式奈米材料，相較於矽晶基材與矽晶奈米柱擁有更優異的光吸收能力，且透過金薄膜產生的表面電漿共振效應可大幅提升近紅外光波段的光吸收。此外，若奈米管之間排列較緊密，因靜電屏蔽效應而嚴重影響場發射性質，因此本實驗嘗試以相同製備手法製備出間距較大、不同尺寸之矽單晶奈米管陣列結構。由場發射性質量測結果顯示，小尺寸下的矽單晶奈米管具有管壁較薄，且相對各個奈米管的間距變大，可以發現其場增強因子從1830提升至2814，起始電場從4.3 V μm-1下降至2 V μm-1，大幅提升場發射的效應。;In this study, we demonstrate a novel approach combining the polystyrene nanosphere lithography and metal-assisted catalyzed etching process to successfully fabricate large-area, well-order arrays of vertically-aligned silicon nanotubes on (001)Si substrates. The inner/outer diameter and length of silicon nanotubes are modulated by controlling the size of the polystyrene nanospheres and the wet etching time. From SEM, TEM and SAED analysis indicated that silicon nanotubes are highly collimated and single crystalline. The Vis-NIR spectroscopic measurements revealed that the silicon nanotubes considered as a hole-in-rod structure exhibited excellent light absorption characteristics compared to silicon nanorods, and the surface plasma resonance effect generated by the gold films can greatly enhance the absorption of NIR light. In addition, if the nanotubes are crowded, the field emission properties are seriously affected by the screening effect. Therefore, this study attempts to fabricate silicon nanotube arrays with larger pitch and different size by the same method. From field emission measurement results show that the field enhancement factor of small-sized silicon nanotubes, owing to their thin wall, large pitch, can be found to increase from 1830 to 2814, and turn-on field was reduced from 4.3 V μm-1 to 2 V μm-1.
