Giant photoconductivity induced by plasmonic Co nanoparticles in Co-doped amorphous carbon/silicon heterostructures
Giant photoconductivity induced by plasmonic Co nanoparticles in Co-doped amorphous carbon/silicon heterostructures
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DOI：
10.1016/j.carbon.2014.01.061
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发表时间：
2014-06
期刊：
影响因子：
10.9
通讯作者：
Yu’e Jiang;J. F. Wang;J. Gao
中科院分区：
文献类型：
--
作者：
Yu’e Jiang;J. F. Wang;J. Gao
利用脉冲激光沉积（PLD）技术在n型Si衬底上生长Co-C薄膜，制备了Co掺杂非晶碳/硅（Co-C/Si）异质结构，并在该异质结构中观察到了巨大的光电导。当样品用1 mW/cm ~ 2的低密度单色光照射时，所获得的光敏性（定义为光电导σ p与暗电导率σd之比）高达105。光电导的光谱依赖性表现出显着的光敏性在一个大的光谱范围内，并表现出一个峰值的光敏性约为710 nm。透射电子显微镜（TEM）显示自组装钴纳米粒子在无定形碳层。与Co-C/Si异质结构相比，无Co纳米颗粒的纯非晶碳（a-C）/Si异质结构也没有发现明显的光电导，其巨大的光电导机制可能是由于Co纳米颗粒的表面等离子体共振（SPR）吸收。
A giant photoconductivity was observed in heterostructures of Co-doped amorphous carbon/silicon (Co–C/Si), which were fabricated by growing Co–C films on n-type Si substrates through pulsed laser deposition (PLD). When the sample was illuminated by a monochromatic light with a small density of 1 mW/cm2, the obtained photosensitivity, defined as the ratio of the photoconductivityσpto the dark conductivityσd, was as large as ∼105. Spectral dependence of the photoconductivity demonstrated significant photosensitivity in a large spectrum range and exhibited a peak photosensitivity around ∼710 nm. Transmission electron microscopy (TEM) revealed self-assembled cobalt nanoparticles in the amorphous carbon layer. In comparison with Co–C/Si heterostructures, the pure amorphous carbon (a-C)/Si heterostructure without Co nanoparticles was also fabricated and no significant photoconductivity was found. The mechanism of giant photoconductivity might be attributed to the surface plasmon resonance (SPR) absorption of Co nanoparticles.