School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, 130033, P.R. China.
Sci Rep. 2016 Nov 23;6:37496. doi: 10.1038/srep37496.
Giant optical transmittance changes of over 300% in wide wavelength range from 500 nm to 2500 nm were observed in LaBaCoO thin films annealed in air and ethanol ambient, respectively. The reduction process induces high density of ordered oxygen vacancies and the formation of LaBaCoO (δ = 0) structure evidenced by aberration-corrected transmission electron microscopy. Moreover, the first-principles calculations reveal the origin and mechanism of optical transmittance enhancement in LaBaCoO (δ = 0), which exhibits quite different energy band structure compared to that of LaBaCoO (δ = 0.5). The discrepancy of energy band structure was thought to be the direct reason for the enhancement of optical transmission in reducing ambient. Hence, LaBaCoO thin films show great prospect for applications on optical gas sensors in reducing/oxidizing atmosphere.
在空气和乙醇环境中退火的 LaBaCoO 薄膜中观察到了超过 300%的大光学透过率变化，波长范围从 500nm 到 2500nm。还原过程导致高密度有序氧空位的形成和 LaBaCoO(δ=0)结构的形成，这一点通过相衬透射电子显微镜得到了证实。此外，第一性原理计算揭示了 LaBaCoO(δ=0)中光学透过率增强的起源和机制，与 LaBaCoO(δ=0.5)相比，它表现出非常不同的能带结构。能带结构的差异被认为是在还原环境中增强光学透过率的直接原因。因此，LaBaCoO 薄膜在还原/氧化气氛下的光学气体传感器应用方面具有广阔的前景。
