论文标题
由金属辅助化学蚀刻制造的Si微柱阵列的异质光电特性
Heterogeneous Optoelectronic Characteristics of Si Micropillar Arrays Fabricated by Metal-Assisted Chemical Etching
论文作者
论文摘要
在金属辅助化学蚀刻（MACE）中取得的最新进展已使为各种光电应用的高质量微柱阵列生产。 MACE生产的Si微柱经常在局部电化学反应引入的晶体核心上显示多孔Si/Siox壳。在本文中，我们报告了多孔Si/Siox壳的独特光电特性与它们的化学成分相关。共聚焦显微镜中使用浸入油物镜获得的局部光致发光（PL）图像显示，沿支柱周长的红色发射峰（约650 nm）与其中心相比要强三倍。根据我们的分析，我们发现油/壳界面处的PL提高（约540 nm）。我们建议这两种PL增强功能主要归因于多孔结构，这是在先前的MACE研究中观察到的类似行为。与地形同时记录的表面电势图揭示了MACE合成柱（+0.5 V）的侧壁上的表面电位明显高，该柱的侧壁电势将在氢氟酸中删除SiOx后，将其恢复到平面Si控制（-0.5 V）的水平。 Si/Siox壳的这些独特的光电特性可能对各种传感器架构有益。
Recent progress achieved in metal-assisted chemical etching (MACE) has enabled the production of high-quality micropillar arrays for various optoelectronic applications. Si micropillars produced by MACE often show a porous Si/SiOx shell on crystalline pillar cores introduced by local electrochemical reactions. In this paper, we report the distinct optoelectronic characteristics of the porous Si/SiOx shell correlated to their chemical compositions. Local photoluminescent (PL) images obtained with an immersion oil objective lens in confocal microscopy show a red emission peak (about 650 nm) along the perimeter of the pillars that is threefold stronger compared to their center. On the basis of our analysis, we find an unexpected PL increase (about 540 nm) at the oil/shell interface. We suggest that both PL enhancements are mainly attributed to the porous structures, a similar behavior observed in previous MACE studies. Surface potential maps simultaneously recorded with topography reveal a significantly high surface potential on the sidewalls of MACE-synthesized pillars (+0.5 V), which is restored to the level of planar Si control (-0.5 V) after removing SiOx in hydrofluoric acid. These distinct optoelectronic characteristics of the Si/SiOx shell can be beneficial for various sensor architectures.
