Abstract In this work, the effect of the very low substrate temperature and hydrogen dilution on chemical, structural, and optical properties of polymorphous silicon thin films (pm-Si:H) using dichlorosilane as a silicon gas precursor in the plasma enhanced chemical vapor deposition (PECVD) was analyzed. The films were synthesized at a lower deposition temperature in the range from 60 to 150 °C and two H2 dilutions of 60 and 100 sccm. Hydrogen incorporation in silicon thin films has been studied by Elastic Recoil Detection Analysis (ERDA) and Fourier Transform Infrared Spectroscopy (FTIR). FTIR was also used to verify the chemical stability of the material as a function of oxidation state and hydrogen effusion. The ERDA analysis evidenced that the hydrogen content typically does not exceed 30 at. %, and the lowest value obtained is around 10 at. %. With Raman spectroscopy, the crystalline fraction was obtained in the range of 5–20%, and the average size of the embedded nanocrystals was found to be between 2 and 3 nm, which was cross-checked by High-Resolution Transmission Electron Microscopy (HRTEM). Finally, by UV–Vis spectroscopy, the effective optical band gap of this material has been calculated, and the value was found to be around 1.6 eV (absorber layer) for the samples with 100 sccm of H2 dilution and around 2.2 eV (window layer) for the samples with 60 sccm of H2 dilution. Overall the increase in the substrate temperature resulted a better ordering in the amorphous matrix, whereas, with the increase in the hydrogen dilution an improvement in the structure factor was observed. Suitable properties of the deposited material in the present work could be useful for the development of a thin silicon layer for different silicon solar cell technologies.

中文翻译：

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使用氯化前体和光学特性的硅薄膜的极低温生长

摘要 在这项工作中，在等离子体增强化学气相沉积中，极低的衬底温度和氢稀释对使用二氯硅烷作为硅气体前驱体的多晶硅薄膜 (pm-Si:H) 的化学、结构和光学性能的影响(PECVD) 进行了分析。这些薄膜是在 60 到 150 °C 的较低沉积温度和 60 和 100 sccm 的两种 H2 稀释度下合成的。已通过弹性反冲检测分析 (ERDA) 和傅立叶变换红外光谱 (FTIR) 研究了硅薄膜中的氢掺入。FTIR 还用于验证作为氧化态和氢渗出函数的材料的化学稳定性。ERDA 分析证明氢含量通常不超过 30 at。%，获得的最低值约为 10 at。%。使用拉曼光谱，获得的结晶分数在 5-20% 的范围内，并且发现嵌入的纳米晶体的平均尺寸在 2 和 3 nm 之间，这通过高分辨率透射电子显微镜（HRTEM）进行了交叉检查）。最后，通过紫外-可见光谱，计算了该材料的有效光学带隙，发现对于具有 100 sccm H2 稀释和约 2.2 eV（窗口层）的样品，该值约为 1.6 eV（吸收层） ) 用于 H2 稀释为 60 sccm 的样品。总体而言，衬底温度的增加导致非晶基质中更好的有序性，而随着氢稀释度的增加，观察到结构因子的改善。