论文标题
纳米晶体化的Aln的光学表征：通过磁控溅射制备的ER膜
Optical characterization of nanocrystallized AlN:Er films prepared by magnetron sputtering
论文作者
论文摘要
为了了解掺杂的Erbium和靶向光子应用的Aln膜的光致发光机制，我们通过使用PVD Magnetron溅射合成了具有不同结晶纳米结构的非掺杂和ER掺杂的ALN膜。它们的结晶形态和可见的光致发光特性得到了精确测量。到弱稀土等弱横截面吸收（如Erbium），有必要在宿主基质和稀土之间获得有效的能量传递机制，以获得高发光效率。然后，由于存在结构缺陷（点缺陷，晶粒边界{\ ldots}）的存在，我们的策略是要详细介绍一些纳米结构，这些纳米结构可能会在差距内引入其他中间电子水平，并且可以通过无线电频率启动型号来详细介绍，并且可以通过详细的范围来制备稀有地球和非上方的Aln膜的能量传递，并可以通过稀有的地球进行详细范围。在沉积过程中，样品的负极极化如何允许获得从经典柱状结构到具有多种纳米晶粒（几乎是无定形）的高度无序的多晶结构的结晶形态。胶片的纳米结构可以分为三种类型：1）1型是纳米coloclumnar（〜15 nm列的宽度），2）2）2）用短列（〜10 nm列的宽度宽度）制成，最后类型的类型是由等轴纳米晶体制成的（晶粒的大小〜3-4 nm nm）。样品在458、488或514 nm处被激光波长激发。在柱状样品中观察到宽阔的光致发光条带约520 nm。在相同的能量范围内，高度分辨的光谱也显示出几个尖锐的发射峰。这种精细的结构可以归因于Erbium的转变。这种精细的结构倾向于从1型到3型样品中消失。实际上，峰的相对强度降低，最大峰值的全宽度增加。这种变化可能与当谷物尺寸减小时增加的缺陷密度有关。可见范围内膜的光致发光特性将与它们的结构讨论。
In the prospect of understanding the photoluminescence mechanisms of AlN films doped with erbium and targeting photonic applications we have synthesized non doped and Er-doped AlN films with different crystallized nanostructures by using PVD magnetron sputtering. Their crystalline morphology and their visible photoluminescence properties were precisely measured.Due to the weak cross-section absorption of rare earths like erbium, it is necessary to obtain an efficient energy transfer mechanism between the host matrix and the rare earth to obtain high luminescence efficiency. Our strategy is then to elaborate some nanostructures that could introduce additional intermediate electronic levels within the gap thanks to the presence of structural defects (point defects, grain boundaries{\ldots}) and could lead to energy transfer from the AlN matrix to the rare earth.Doped and non-doped AlN films were prepared by radio frequency magnetron sputtering by using different experimental conditions that will be detailed. It will notably be shown how a negative polarization of samples during deposition allows obtaining crystalline morphologies ranging from the classical columnar structure to a highly disordered polycrystalline structure with grains of several nanometers (nearly amorphous). The nanostructures of the films could be categorized in three types: 1) type 1 was nanocolumnar (width of column ~ 15 nm), 2) type 2 was made of short columns (width of column ~ 10 nm) and 3) the last type was made of equiaxed nanocrystallites (size of grains ~3-4 nm).High-resolution photoluminescence spectroscopy was performed to characterize their optical behaviour. The samples were excited by the laser wavelengths at 458, 488 or 514 nm. A broad photoluminescence band was observed centred around 520 nm in columnar samples. In the same energy range, the highly resolved spectra also showed several sharp emission peaks. This fine structure could be attributed to erbium transitions. This fine structure tended to disappear going from type 1 to type 3 samples. Indeed, the relative intensity of the peaks decreased and their full width at half maximum increased. This change could be related to the density of defects that increased when the size of the grains decreased. The photoluminescence properties of the films in the visible range will be discussed in relation with their structure.
