Influence of chromium concentration on the optical–electronic properties of ruby microstructures
Influence of chromium concentration on the optical–electronic properties of ruby microstructures
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DOI：
10.1088/0022-3727/43/1/015302
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发表时间：
2010-01
期刊：
影响因子：
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通讯作者：
L. C. Cossolino;A. Zanatta
中科院分区：
文献类型：
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作者：
L. C. Cossolino;A. Zanatta
在纯氮等离子体中，采用常规射频溅射Al + Cr靶制备了非晶氮化铝（AlN）薄膜。Cr与Al的相对面积决定了Cr含量，在本研究中，Cr含量保持在100 -3.5原子%的浓度范围内。薄膜沉积之后，在氧气气氛中对样品进行高达1050 °C的热退火，并通过能量色散X射线光谱法、光致发光和光学透射测量进行光谱表征。根据实验结果，含铬氮化铝薄膜的光电性能的高度影响的Cr浓度和热处理温度。事实上，在1050 °C的热退火诱导了结构的发展，由于其典型的尺寸和独特的光谱特征，被称为红宝石显微结构（RbMS）。这些RbMS被富氮环境包围，其中Cr 3+离子表现出其他含Cr 3+系统（如红宝石、祖母绿或翠绿宝石）中不存在的发光特征。根据Cr浓度和测量温度，研究了RbMS和周围环境所示的光发射，从而确定了几个Cr 3+相关的发光线。这些发光线和相应的激发复合过程的主要特点，并讨论了在一个详细的光谱分析。
Films of amorphous aluminium nitride (AlN) were prepared by conventional radio frequency sputtering of an Al + Cr target in a plasma of pure nitrogen. The Cr-to-Al relative area determines the Cr content, which remained in the ∼0–3.5 at% concentration range in this study. Film deposition was followed by thermal annealing of the samples up to 1050 °C in an atmosphere of oxygen and by spectroscopic characterization through energy dispersive x-ray spectrometry, photoluminescence and optical transmission measurements. According to the experimental results, the optical–electronic properties of the Cr-containing AlN films are highly influenced by both the Cr concentration and the temperature of the thermal treatments. In fact, thermal annealing at 1050 °C induces the development of structures that, because of their typical size and distinctive spectral characteristics, were designated by ruby microstructures (RbMSs). These RbMSs are surrounded by a N-rich environment in which Cr3+ ions exhibit luminescent features not present in other Cr3+-containing systems such as ruby, emerald or alexandrite. The light emissions shown by the RbMSs and surroundings were investigated according to the Cr concentration and temperature of measurement, allowing the identification of several Cr3+-related luminescent lines. The main characteristics of these luminescent lines and corresponding excitation–recombination processes are presented and discussed in view of a detailed spectroscopic analysis.