Optical spectroscopy of Er doped Si-nanocrystals on sapphire substrates fabricated by ion implantation into SiO 2
Optical spectroscopy of Er doped Si-nanocrystals on sapphire substrates fabricated by ion implantation into SiO 2
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离子注入 SiO 2 蓝宝石衬底上掺铒硅纳米晶的光谱
DOI：
10.1117/12.852922
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Hylton N
中科院分区：
文献类型：
--
作者：
Hylton N
我们给出了一系列掺Er纳米硅(Si-NC)样品的光学研究结果，这些样品是通过离子注入到蓝宝石衬底上的二氧化硅中制备的，随后进行了一系列的快速热处理。光致发光光谱表明，随退火条件的变化，发光强度增加，峰值波长红移。我们将前者归因于随退火温度/时间的增加，注入缺陷的减少。对室温下光致发光强度衰减率的测量表明，载流子寿命相应增加，这也表明非辐射中心的贡献减少。峰值Si-NC强度的红移归因于平均Si-NC尺寸随退火条件的变化而增大。对相对Er增感的估算表明，最小的Si-NC尺寸分布导致最大的增感比。用激发光谱的形式进一步研究表明，Er离子不仅通过来自Si-NCS的能量传递而敏化，而且更重要的是来自SiO_2中的缺陷态的敏化。
We present the results of an optical investigation of a series of Er doped silicon nanocrystal (Si-NC) samples which were fabricated via ion implantation into SiO2on sapphire substrates, followed by a range of rapid thermal processing. The photoluminescence spectra of the Si-NC emission revealed an increase in luminescence intensity and a red-shift of the peak wavelength as a function of annealing conditions. We attribute the former effect to the reduction of implantation induced defects with increasing annealing temperature/duration. Measurements of the rate of decay of photoluminescence intensity at room temperature show a corresponding increase in the carrier lifetimes which is also an indication of a reduced contribution from non-radiative centers. The red-shift of the peak Si-NC intensity is ascribed to an increasing mean Si-NC size as a function of the annealing conditions. Also presented is an estimation of the relative Er sensitization which reveals that the smallest Si-NC size distribution leads to the greatest sensitization ratio. Further investigation in the form of excitation spectroscopy was used to show that Er ions are sensitized not only by energy transfer from the Si-NCs, but also, crucially, from defect states in the SiO2.