有良好光吸收性的材料對於光偵測元件的應用非常重要。在本研究中，我們成功在矽晶基材上利用奈米球微影技術結合金屬催化蝕刻法以一步驟蝕刻來製備大面積、尺寸可調之規則矽晶奈米錐陣列，並探討其在波長400-1600 nm之光吸收特性，相較純矽晶基材及矽晶奈米柱可明顯提升光吸收效果。接著藉由矽晶奈米錐陣列能有效提升光吸收之特性，蒸鍍鎳金屬薄膜於矽晶奈米錐陣列上形成蕭基接面以製作光偵測器，並對於背鍍鋁電極之鎳/矽晶奈米錐陣列進行光譜量測分析，發現奈米錐側壁之尖針狀的鎳金屬薄膜，可大幅增加試片對近紅外光的吸收率，在波長400-1600 nm皆達90 %以上，說明對於紅外光的應用具有相當大的潛力。鎳/矽晶奈米錐蕭基接面在暗態下表現出明顯的整流特性，並可於無外加偏壓下，以波長940 nm近紅外光源照射實現自驅動光偵測特性，同時得到良好的光響應電流，並具有響應快速、高穩定性等優勢。;In this study, we propose a facile approach, which is based on the oxygen plasma modified nanosphere lithography in conjunction with a one-step Au-assisted chemical etching process to fabricate periodic arrays of vertically-aligned, size-controllable Si nanocones on p-type (001)Si substrates. UV-Vis-IR spectroscopic measurements showed that the produced high-aspect-ratio, vertical Si nanocone array exhibited good broadband absorption characteristics in the wavelength range of 400-1600 nm, which have promising applications in near-infrared (near-IR) photodetection. To fabricate a Si nanocone-based near-IR photodetector, a Ni thin film was deposited on the surface of the p-type vertical Si nanocone array. The produced core-shell (Si nanocone array/Ni) Schottky junction near-IR photodetector is self-powered, and can generate a photocurrent under 940 nm illumination at zero bias voltage with a considerable on/off ratio (~103). Furth device analyses also show that the produced self-powered photodetector exhibits high responsivity, good stability, and fast response and recovery time. The obtained results clearly demonstrate that the new approach proposed here provides the capability to fabricate various high-performance, self-powered Si-based IR photodetectors.
