Fundamental temperature-dependent properties of the Si nanocrystal band gap
Fundamental temperature-dependent properties of the Si nanocrystal band gap
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DOI：
10.1103/physrevb.85.165306
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发表时间：
2012-04-12
影响因子：
3.7
通讯作者：
Zacharias, M.
中科院分区：
文献类型：
--
作者：
Hartel, A. M.;Gutsch, S.;Zacharias, M.
自从首次报道硅纳米晶 Si (NC) 的低温光致发光 (PL) 测量以来，就报道了与通常用于描述块体材料带隙能量的温度依赖性的方程的严重偏差。我们的分析表明，之前观察到的偏差完全归因于过高的激发功率密度，由于辐射激子寿命的温度依赖性，导致尺寸分布内较小NC的优先发射增强。我们报告了量子限制硅的温度相关带隙能量的成功拟合。通过四个尺寸控制的 Si NC 样品（1.5 至 4.5 nm），如果激发功率密度足够低（
Ever since the first reports about low-temperature photoluminescence (PL) measurements of Si nanocrystals Si (NCs), a severe deviation from the equations commonly used to describe the temperature dependence of the band-gap energy for bulk materials was reported. Our analysis reveals that the formerly observed deviation is solely attributed to too high excitation power densities that cause a preferential emission enhancement of the smaller NCs within a size distribution, due to the temperature dependence of the radiative exciton lifetime. We report on the successful fit of the temperature-dependent band-gap energy of quantum-confined silicon. By means of four size-controlled Si NC samples (1.5 to 4.5 nm), we are able to prove the validity of these equations down to liquid He temperatures, if sufficiently low excitation power densities (