Data and figures related to publication: Improved ambient stability of thermally annealed Zinc Nitride thin films

Zinc nitride films are known to readily oxidize in an ambient atmosphere, forming a ZnO/Zn(OH)2 medium. We report that post-growth thermal annealing significantly improves the stability of zinc nitride with a three-order magnitude increase in degradation time from a few days in un-annealed films to several years after annealing. A degradation study was performed on samples annealed under a flow of nitrogen at 200–400 °C, which showed that the stability of the films depends strongly on the annealing temperature. We propose a mechanism for this improvement, which involves a stabilization of the native oxide layer that forms on the surface of zinc nitride films after exposure to ambient conditions. The result holds significant promise for the use of zinc nitride in devices where operational stability is a critical factor in applications.<br><br>The study reported in this paper was funded by the EPSRC (Fund code EP/M507611/1) and Johson Matthey PLC. The financial support by these parties is highly appreciated.<br><br>The data required to reproduce each figure panel is provided in different text files. Columns are separated by a space character. The first line in each column describes the dataset. The complete figures are also included as .tif files.<br><br>With the added context of the paper, it should be easy to reproduce the figures.<br><br><b>Figure 1:</b> Transmittance spectra of (a) an as-deposited and (b) an annealed 700 nm Zn₃N₂ film for up to 18 weeks. (c) Scanning Electron Microscopy image of a partially oxidised Zn₃N₂ film.<br><b><br>Figure 2:</b> (a) Refractive index, n, and (b) extinction coefficient, k, of the Zn₃n₂ layer obtained by spectroscopic ellipsometry for different annealing temperatures.<br><br><b>Figure 3:</b> Thickness of (a) the Zn₃N₂ layer and (b) oxide layers over several months for annealed samples. (c) Lifetime of the Zn₃N₂ layer as a function of annealing temperature. The data points marked with * were extrapolated based on the oxidation rates measured in this study.<br><br><b>Figure 4:</b> X-ray diffraction scans of the (400) peak for Zn₃N₂ samples annealed at different temperatures. The dashed line shows the expected position of the (400) peak based on crystallographic data.<br><br><br>

氮化锌薄膜在大气环境中极易发生氧化，最终形成氧化锌（ZnO）/氢氧化锌（Zn(OH)₂）复合介质。本研究发现，生长后热退火工艺可显著提升氮化锌薄膜的结构稳定性：未退火薄膜的降解时长仅为数天，经退火处理后降解时长可延长至数年，提升幅度达三个数量级。我们对在200~400℃氮气气流氛围下退火的样品开展了降解性能研究，结果表明薄膜稳定性与退火温度密切相关。针对该稳定性提升现象，我们提出了相关作用机制：暴露于大气环境后，氮化锌薄膜表面会自然形成氧化层，退火工艺可稳定该自然氧化层结构。该研究结果为氮化锌在对运行稳定性有严苛要求的器件中的应用提供了重要的应用前景。

本研究受工程与物理科学研究委员会（EPSRC，资助编号EP/M507611/1）以及庄信万丰股份有限公司（Johnson Matthey PLC）资助，在此谨对上述机构的资金支持致以诚挚谢意。

复现每张图所需的实验数据均存储于不同的文本文件中，各列数据以空格符分隔，每列的首行用于说明该数据集的内容。完整的原图均以.tif格式文件提供。

结合本论文提供的背景信息，即可轻松复现所有实验图。

<b>图1：</b>（a）初始沉积态、（b）经退火处理的700 nm厚氮化锌（Zn₃N₂）薄膜在18周内的透射光谱；（c）部分氧化的氮化锌薄膜的扫描电子显微镜（Scanning Electron Microscopy，SEM）图像。

<b>图2：</b>（a）不同退火温度下通过光谱椭偏术测得的氮化锌薄膜的折射率n与（b）消光系数k。

<b>图3：</b>（a）退火样品的氮化锌薄膜层与（b）氧化层在数月内的厚度变化；（c）氮化锌薄膜的寿命随退火温度的变化关系。图中带*标记的数据点为本研究基于氧化速率实测值外推得到的结果。

<b>图4：</b>不同退火温度下氮化锌样品的（400）晶面X射线衍射扫描图谱，虚线为基于晶体学数据计算得到的（400）峰理论位置。