Abstract Cadmium Telluride (CdTe) is an important material for the production of high-efficiency thin-film solar cells. While sputter deposition has been used to create CdTe-based solar cells, two other important methods of growth are close-spaced sublimation and vapor deposition. In these methods, the depositing clusters correspond to Cd atoms and Te2 dimers while the deposition energies are relatively low. In addition, depending on vapor pressure, deposition method, and target-substrate distance, deposition may occur at relatively large angles with respect to the substrate normal. Here we investigate the dependence of the attachment probability and deposition site for Cd and Te2 clusters deposited on Cd-terminated and Te-terminated (100) and (111) surfaces of zincblende CdTe on deposition conditions. In general, we find that the deposition of Cd atoms and/or Te2 dimers on the oppositely terminated surface leads to an attachment probability which is close to 1 and relatively independent of deposition conditions for both the (100) and (111) orientations. In contrast, deposition on the same terminated surface leads to a significantly lower attachment probability which generally decreases with increasing deposition angle, energy, and substrate temperature. Our results also indicate that deposition on the (111) surface leads to a significant excess Te sticking probability. In contrast, the excess Te attachment probability for deposition on the (100) surface is typically significantly smaller, and in some cases may even be negative. We also find, for both deposition on the (111) surface as well as opposite termination deposition on the (100) surface, that the dominant deposition mode corresponds to sitting on top of the surface which corresponds to growth of the next layer. In contrast, for same termination deposition on the (100) surface the dominant deposition mode corresponds to joining the first layer. These results imply that even for low deposition energies and substrate temperatures, deposition on the (100) surface is likely to create interstitials in the surface layer.

中文翻译：

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沉积在 CdTe 上的 Cd 和 Te2 的能量、温度和沉积角度依赖性

摘要 碲化镉（CdTe）是生产高效薄膜太阳能电池的重要材料。虽然溅射沉积已被用于制造基于 CdTe 的太阳能电池，但另外两种重要的生长方法是近距离升华和气相沉积。在这些方法中，沉积簇对应于 Cd 原子和 Te2 二聚体，而沉积能量相对较低。此外，根据蒸气压、沉积方法和目标-基板距离，沉积可能以相对于基板法线的较大角度发生。在这里，我们研究了沉积在闪锌矿 CdTe 的 Cd 封端和 Te 封端的 (100) 和 (111) 表面上的 Cd 和 Te2 簇的附着概率和沉积位点对沉积条件的依赖性。一般来说，我们发现 Cd 原子和/或 Te2 二聚体在相反终止的表面上的沉积导致附着概率接近 1 并且相对独立于 (100) 和 (111) 方向的沉积条件。相比之下，在相同终止表面上的沉积导致附着概率显着降低，这通常随着沉积角度、能量和基板温度的增加而降低。我们的结果还表明，（111）表面上的沉积导致显着的过量 Te 粘附概率。相比之下，在 (100) 表面沉积的过量 Te 附着概率通常要小得多，在某些情况下甚至可能为负。我们还发现，对于（111）表面上的沉积以及（100）表面上的相反终止沉积，主要沉积模式对应于位于表面的顶部，这对应于下一层的生长。相反，对于(100)表面上的相同终止沉积，主要沉积模式对应于连接第一层。这些结果意味着即使对于低沉积能量和基板温度，(100) 表面上的沉积也可能在表面层中产生间隙。