Structural and optoelectronic properties of selenium-doped silicon formed using picosecond pulsed laser mixing
Structural and optoelectronic properties of selenium-doped silicon formed using picosecond pulsed laser mixing
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使用皮秒脉冲激光混合形成的硒掺杂硅的结构和光电特性
DOI：
10.1002/pssa.201228202
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发表时间：
2012-12-01
影响因子：
2
通讯作者：
Gao, Lipeng
中科院分区：
文献类型：
--
作者：
Hu, Shaoxu;Han, Peide;Gao, Lipeng
微结构硅掺杂超过平衡固溶度极限的硒形成了皮秒脉冲激光混合的20 nm的硒膜与下面的p-Si晶片。研究了脉冲能量密度在0.40 ~ 0.72 J cm（-2）范围内变化对材料结构和电子性质的影响。结果表明，激光辐照区的表面粗糙度随脉冲能量密度的增加而增加，当脉冲能量密度为0.72 J cm（-2）时，发生了由晶态到非晶态的相变。硅微结构在表面以下100 nm的深度内掺杂10（18）cm（-3）量级的硒，并且在Se掺杂层和硅衬底之间形成n（+）p结。对微结构硅光电二极管的电流-电压特性和光谱响应特性进行了分析和讨论。这些光电二极管的漏电流和响应度强烈地依赖于脉冲能量密度，这可能是由于皮秒激光对表面Se掺杂层的晶体结构和电子结构的改性的影响。(C)2012 WILEY- VCH Verlag GmbH & Co. KGaA，魏因海姆
Microstructured silicon doped with selenium beyond the equilibrium solid solubility limit was formed by picosecond pulsed laser mixing of a 20-nm Se film with the underlying p-Si wafer. The effects of pulse fluence varying from 0.40 to 0.72 J cm(-2) on the structural and electronic properties of this material were investigated. It was found that the surface roughness in the laser-irradiated regions increases with increasing pulse fluence, and a phase transition from the crystalline to the amorphous occurs at a pulse fluence of 0.72 J cm(-2). Silicon microstructures were doped with selenium of the order of 10(18) cm(-3) within a depth of 100 nm below the surface, and n(+)p junctions were formed between the Se-doped layers and the silicon substrates. The current-voltage as well as spectral response characteristics of the photodiodes fabricated from microstructured silicon were also analyzed and discussed. The leakage currents and responsivities of these photodiodes strongly depend on the pulse fluence, presumably due to the effects of picosecond laser modification on the crystal structure and electronic structure of the surface Se-doped layers. (C) 2012 WILEY- VCH Verlag GmbH & Co. KGaA, Weinheim