Structure-property relationships and mobility optimization in sputtered La-doped BaSnO3 films: Toward 100cm2V−1s−1 mobility
Structure-property relationships and mobility optimization in sputtered La-doped BaSnO3 films: Toward 100cm2V−1s−1 mobility
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DOI：
10.1103/physrevmaterials.5.044604
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发表时间：
2021-04
影响因子：
3.4
通讯作者：
W. Postiglione;K. Ganguly;H. Yun;J. Jeong;A. Jacobson;Lindsey Borgeson;B. Jalan;K. Mkhoyan
中科院分区：
文献类型：
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作者：
W. Postiglione;K. Ganguly;H. Yun;J. Jeong;A. Jacobson;Lindsey Borgeson;B. Jalan;K. Mkhoyan
宽禁带半导体钙钛矿材料由于在高电子密度下具有优异的室温迁移率，在氧化物、透明和电力电子方面的潜在应用而引起了人们的高电流兴趣。然而，部分由于缺乏晶格匹配的衬底，薄膜存在高缺陷密度，限制了电子的迁移率。此外，绝大多数薄膜研究都集中在脉冲激光沉积或分子束外延方面。在这里，我们提出了一种可扩展、高通量生长的薄膜迁移率的全面优化方法：高压氧溅射沉积。综合考虑靶材合成条件、衬底选择、缓冲层结构、沉积温度、沉积速率、厚度、沉积后退火条件，结合高分辨率X射线衍射、倒易空间映射、摇摆曲线分析、扫描电子显微镜、原子力显微镜和随温度变化的电子输运测量，对合成-结构-性能之间的关系有了详细的了解。在真空退火的(110)/(120 Nm)/(200 Nm)异质结中，以及在无缓冲衬底和不需要沉积后退火的情况下，实现了最佳的室温迁移率。这些结果，包括缺陷密度的重要趋势和迁移率对晶格失配的惊人依赖，极大地扩展了对掺杂薄膜中沉积条件、微结构和输运之间相互作用的理解，建立了通过可扩展、高通量、行业标准技术制备的薄膜的竞争迁移率。
The wide band gap semiconducting perovskiteis of high current interest due to outstanding room temperature mobility at high electron density, fueled by potential applications in oxide, transparent, and power electronics. Due in part to a lack of lattice-matched substrates,thin films suffer from high defect densities, however, limiting electron mobility. Additionally, the vast majority ofthin film research has focused on pulsed laser deposition or molecular beam epitaxy. Here, we present an exhaustive optimization of the mobility offilms grown by a scalable, high-throughput method: high-pressure-oxygen sputter deposition. Considering target synthesis conditions, substrate selection, buffer layer structure, deposition temperature, deposition rate, thickness, and postdeposition annealing conditions, and by combining high-resolution x-ray diffraction, reciprocal space mapping, rocking curve analysis, scanning transmission electron microscopy, atomic force microscopy, and temperature-dependent electronic transport measurements, detailed understanding of synthesis-structure-property relationships is attained. Optimized room temperature mobility ofis achieved in vacuum-annealed(110)/(120 nm)/(200 nm) heterostructures, as well ason unbuffered substrates andwithout postdeposition annealing. These results, including important trends in defect densities and a surprising dependence of mobility on lattice mismatch, substantially expand the understanding of the interplay between deposition conditions, microstructure, and transport in dopedfilms, establishing competitive mobilities in films fabricated via a scalable, high-throughput, industry-standard technique.