Wu Kai, Geng Wan-Rong, Zhu Yin-Lian, Ma Xiu-Liang
Bay Area Center for Electron Microscopy, Songshan Lake Materials Laboratory, Dongguan 523808, China.
Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Materials (Basel). 2025 Apr 8;18(8):1696. doi: 10.3390/ma18081696.
As one of the representative transparent conducting oxides, perovskite-typed La-doped BaSnO (LBSO) films could be integrated with other perovskite materials to create all-perovskite oxide devices exhibiting exotic physical properties. To overcome the intricate trade-off between conductivity and transmittance in LBSO-based devices, understanding the structural modulating mechanisms of transmittance is definitely crucial. In this paper, the influences of the prevailing Ruddlesden-Popper faults (RP faults) on the transmittance of LBSO films were systematically illuminated, whose density were regulated by the oxygen partial pressures during film growth. High-angle annular dark field (HAADF) STEM and X-ray diffraction (XRD) were employed to characterize the microstructures of the films growing under various oxygen partial pressures and annealing under different oxygen partial pressures. A decrease in RP fault density was observed in the films grown and annealed at high oxygen partial pressures, which displayed improved visible light transmittance. Atomic-scale energy-dispersive spectroscopy (EDS) and electron energy-loss spectroscopy (EELS) analyses revealed the different electronic structure at RP faults compared with the bulk material, including the double concentration of La and increased M5/M4 white line ratio, which is modulative by the oxygen deficiency in LBSO film. It is revealed that the RP defaults in LBSO films annealed at low oxygen pressures displayed larger changes in electronic structure compared with the counterparts with low oxygen deficiency. This work suggests that the oxygen deficiency in LSBO films plays a crucial role in changing the density of RP faults and their electronic structures, thereby regulating the transmittance of LBSO films, which would provide guidance for fabricating high-performance LBSO films.
作为代表性的透明导电氧化物之一，钙钛矿型镧掺杂锡酸钡（LBSO）薄膜可与其他钙钛矿材料集成，以制造具有奇异物理特性的全钙钛矿氧化物器件。为了克服基于LBSO的器件中电导率和透光率之间复杂的权衡关系，了解透光率的结构调制机制绝对至关重要。本文系统地阐明了普遍存在的Ruddlesden-Popper缺陷（RP缺陷）对LBSO薄膜透光率的影响，其密度在薄膜生长过程中由氧分压调节。采用高角度环形暗场（HAADF）扫描透射电子显微镜（STEM）和X射线衍射（XRD）来表征在不同氧分压下生长并在不同氧分压下退火的薄膜的微观结构。在高氧分压下生长和退火的薄膜中观察到RP缺陷密度降低，其可见光透光率有所提高。原子尺度的能量色散谱（EDS）和电子能量损失谱（EELS）分析表明，与块状材料相比，RP缺陷处的电子结构不同，包括La的双重浓度和增加的M5/M4白线比，这可由LBSO薄膜中的氧缺陷调节。结果表明，与低氧缺陷的对应物相比，在低氧压力下退火的LBSO薄膜中的RP缺陷在电子结构上表现出更大的变化。这项工作表明，LSBO薄膜中的氧缺陷在改变RP缺陷的密度及其电子结构方面起着关键作用，从而调节LBSO薄膜的透光率，这将为制备高性能LBSO薄膜提供指导。
