Temperature-dependent Raman scattering of the Ge + GeOx system and its potential as an optical thermometer
Temperature-dependent Raman scattering of the Ge + GeOx system and its potential as an optical thermometer
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DOI：
10.1016/j.rinp.2020.103500
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发表时间：
2020-10
影响因子：
5.3
通讯作者：
A. Zanatta
中科院分区：
文献类型：
--
作者：
A. Zanatta
对各种Ge基样品的声子行为进行了详细的研究。该研究包括锗薄膜（非晶和部分结晶和氧合金），晶体锗晶片（原始和氧合金），和GeO 2粉末。热退火Ge薄膜和Ge晶片后得到的含氧样品对应于亚化学计量的GeO 2，或所谓的Ge+ GeOx系统，在这种情况下[O] ≤ 40 at.%。通过温度相关的拉曼散射，根据现有的理论模型（包括非谐声子耦合和热膨胀过程）对Ge+ GeO x系统进行了彻底的研究，并对文献进行了严格的审查，表明实际上独立的Ge-Ge和Ge-O相关结构共存，并确认了结构和化学（无序）秩序的存在。此外，Ge+ GeOx系统的声子频率（ω）、线宽（γ）和散射强度（IS）的主要特征表明了它们在温度传感应用中的适用性。因此，实验确定的参考曲线（即，用简单的数学函数描述的ω T、γ T和I S T数据）使温度精度达到20 K。考虑到一切，在其目前的形式，这项工作提出了第一个全面的分析，讨论有关的Ge+ GeO x系统，此外，被提出作为一个有效的介质，光学测温应用。
The phonon behavior of various Ge-based samples has been investigated in great detail. The study comprised Ge films (amorphous and partially crystallized and alloyed with oxygen), crystalline Ge wafers (pristine and alloyed with oxygen), and GeO 2 powder. The oxygen-containing samples obtained after thermal annealing the Ge film and Ge wafer correspond to sub-stoichiometric GeO 2, or the so-called Ge+ GeO x system, in which case [O]∼ 40 at.%. A thorough examination of this Ge+ GeO x system− as provided by temperature-dependent Raman scattering, their analysis according to the existing theoretical models (involving anharmonic phonon coupling and thermal expansion processes), and a critical review of the literature− indicates the coexistence of practically independent Ge− Ge-and Ge− O-related structures and confirms the presence of both structural and chemical (dis) order. Moreover, the main features regarding the phonon frequencies (ω), line widths (γ), and scattering intensities (I S) of the Ge+ GeO x system suggest their suitability in temperature sensing applications. Accordingly, experimentally determined reference curves (ie, ω T, γ T, and I S T data described in terms of simple mathematical functions) gave rise to temperature accuracies on the order of 20 K. Everything considered, in its current form, this work presents the first comprehensive analysis-discussion regarding the Ge+ GeO x system that, additionally, is being proposed as an effective medium for optical thermometric applications.