Achieving high carrier mobilities and low carrier densities has been one of the major challenges in the growth of BaSnO₃ thin films. In this study, unintentional carbon impurities are investigated as one possible cause for poor electrical transport. Carbon concentrations in La-doped BaSnO₃ films grown by molecular beam epitaxy using solid SnO₂ sources are quantified using secondary ion mass spectroscopy. High carbon concentrations of mid-to-low 10¹⁸ atoms/cm³ are detected in samples grown from SnO₂ powder and pellet sources, respectively. The carbon contamination is attributed to adsorbents present on the surface of the air exposed source material. Use of an oxygen plasma during growth does not reduce the amount of carbon detected in the films. Possible steps to reduce carbon contamination are discussed.

中文翻译：

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使用氧化锡源通过分子束外延生长的BaSnO3薄膜中的碳杂质浓度

实现高载流子迁移率和低载流子密度一直是BaSnO ₃薄膜生长的主要挑战之一。在这项研究中，无意中的碳杂质被研究为不良电传输的一种可能原因。使用二次离子质谱法对使用固体SnO ₂源通过分子束外延生长的La掺杂BaSnO ₃薄膜中的碳浓度进行定量。从SnO ₂生长的样品中检测到高碳浓度，低至10 ¹⁸ 原子/ cm ³粉末和颗粒物来源。碳污染归因于暴露在空气中的原料表面上的吸附剂。在生长期间使用氧等离子体不会减少膜中检测到的碳量。讨论了减少碳污染的可能步骤。