论文标题
IN2O3表面的二维电子气体：增强的热电器，电气传输性能及其通过吸附物的降低或补偿受体掺杂
The two-dimensional electron gas of the In2O3 surface: Enhanced thermopower, electrical transport properties, and its reduction by adsorbates or compensating acceptor doping
论文作者
论文摘要
In2O3是N型透明的半导体氧化物，具有表面电子累积层（密封），例如其他几个相关的半导体，例如INAS，INN，SNO2和ZnO。即使密封件在电导率气体传感器中In2O3应用的核心之内，但本文献中缺少该二维电子气体（2DEG）的一致的运输特性。为此，我们研究了高质量的单晶以及纹理的掺杂和未源性的In2O3（111）膜，由等离子体辅助的分子束同育与室温下的室温下的霍尔效应测量，同时通过氧气通过照明来提取霍尔效应测量值，以通过室温在室温下提取密封的传输性能。所得的板电子浓度和密封的迁移率分别为1.5e13 cm^-2和150 cm^2/vs，两者都通过环境空气中与氧气相关的表面吸附物大大降低。我们的运输测量进一步证明了通过与深层补偿受体NI或MG掺杂密封的系统减少。该发现得到了表面带弯曲和密封电子发射的X射线光电子光谱测量。对这些XPS进行定量分析，使用自洽的，耦合的Schroedinger-Poisson计算表明，补偿大量供体缺陷（可能是氧空位）的同时形成几乎完全补偿了散装受体。最后，在In2O3：Seebeck系数测量表面2DEG中，通过降低的尺寸降低来增强热电图，部分降低了3E12和7E12 cm^-2之间的板电子浓度在1E19和2E19和2E19 cm^-3之间的平均浓度在80％之间相比，相当于在80％之间的平均体积浓度，相比之下，相比之下，该材料的平均体积浓度相应，相比之下。电子浓度。
In2O3 is an n-type transparent semiconducting oxide possessing a surface electron accumulation layer (SEAL) like several other relevant semiconductors, such as InAs, InN, SnO2, and ZnO. Even though the SEAL is within the core of the application of In2O3 in conductometric gas sensors, a consistent set of transport properties of this two-dimensional electron gas (2DEG) is missing in the present literature. To this end, we investigate high quality single-crystalline as well as textured doped and undoped In2O3(111) films grown by plasma-assisted molecular beam epitaxy to extract transport properties of the SEAL by means of Hall effect measurements at room temperature while controlling the oxygen adsorbate coverage via illumination. The resulting sheet electron concentration and mobility of the SEAL are 1.5E13 cm^-2 and 150 cm^2/Vs, respectively, both of which get strongly reduced by oxygen-related surface adsorbates from the ambient air. Our transport measurements further demonstrate a systematic reduction of the SEAL by doping In2O3 with the deep compensating bulk acceptors Ni or Mg. This finding is supported by X-ray photoelectron spectroscopy measurements of the surface band bending and SEAL electron emission. Quantitative analyses of these XPS results using self-consistent, coupled Schroedinger-Poisson calculations indicate the simultaneous formation of compensating bulk donor defects (likely oxygen vacancies) which almost completely compensate the bulk acceptors. Finally, an enhancement of the thermopower by reduced dimensionality is demonstrated in In2O3: Seebeck coefficient measurements of the surface 2DEG with partially reduced sheet electron concentrations between 3E12 and 7E12 cm^-2 (corresponding average volume electron concentration between 1E19 and 2E19 cm^-3 indicate a value enhanced by 80% compared to that of bulk Sn-doped In2O3 with comparable volume electron concentration.
