本研究以兩步驟金屬催化無電鍍蝕刻法，成功地在(001)矽單晶基材上製備大面積準直排列之矽單晶奈米線陣列，除此之外，更進一步製備出雙面矽單晶奈米線陣列結構，此雙面結構展現在可見光至近紅外光波段的高吸收能力，且由光學性質量測結果可證明蝕刻後保留於奈米線底部的銀金屬顆粒，在近紅外光波段有大幅提升光吸收之作用。在元件的製程中，本實驗首先在較厚矽單晶基材上開發具有優異近紅外光偵測性能之金/矽蕭基接面元件，並由TEM觀察在奈米線結構上蒸鍍金與鋁金屬薄膜之表面形貌，分別使用940 nm及1300 nm近紅外光光源照射金/矽單晶奈米線陣列蕭基光感測器，在零偏壓下量測其光響應度、偵測靈敏度及響應速度，並將具有最佳性能之元件製程條件直接與超薄可撓曲矽單晶基材整合。 本研究成功製備之超薄矽晶圓具有十分優異的彎曲能力，可撓曲在較大曲率之表面進行光感測，透過在其上製備準直矽單晶奈米線陣列及蕭基接面元件結構，在近紅外光照射下顯示其響應速度及光偵測靈敏度皆有相當優異的表現，同時此超薄矽晶元件可承受多次反覆彎曲，因此具備良好的元件可靠度。本研究最後探討底部銀顆粒對於近紅外光偵測之光電流產生機制，並成功開發設計出可由照射光強度直接調控光電流訊號之矽基近紅外光感測元件，此為近年文獻中較少提及的。;In this study, the two-step metal-catalyzed electroless etching approach is successfully used to fabricate large-area, vertically-aligned single crystalline silicon nanowire arrays (SiNWs) on (001) silicon substrate. In addition, the double-sided SiNWs are further prepared in this study. The double-sided structure exhibits high broadband absorption from visible to near-infrared (NIR) light range, and the large enhancement in NIR range can be attributed to silver-nanoparticles remaining at the bottom of the SiNWs after two-step etching processes. In the fabrication of the NIR photodetectors, we first develop Au/SiNWs Schottky junction on the origin thick Si substrate. By E-beam evaporation, Au and Al metal thin film are deposited on the top surface of SiNWs, and their morphologies are observed by TEM analysis. The produced Au/SiNWs Schottky junction NIR photodetectors are able to operate at zero external bias voltage and exhibite high responsivity, sensitivity and rapid response time to 940 nm and 1300 nm NIR light. The flexible Au/SiNWs Schottky junction NIR photodetectors are demonstrated by combining with ultra-thin Si substrate which has excellent bending ability, and it can be applied to achieve detection of NIR light on larger curvature surface. Furthermore, the produced flexible NIR photodetectors exhibit excellent reliability which can withstand several bending cycles. Finally, the mechanisms of photocurrent generation by Au/SiNWs Schottky junction and Ag nanoparticles under NIR light illumination are dicussed, and we successfully developed SiNWs-based NIR photodetector that can directly modulate the photocurrent signal by using different intensity of the NIR light, which is less mentioned in the literature.
