To achieve a better material for uncooled infrared (IR) detector, polycrystalline VO2(B) thin films with layered W-doping were fabricated on Si substrates by magnetron sputtering, and the best temperature coefficient ...To achieve a better material for uncooled infrared (IR) detector, polycrystalline VO2(B) thin films with layered W-doping were fabricated on Si substrates by magnetron sputtering, and the best temperature coefficient of resistance (TCR) value reached -4.1%/K. The film synthesis was in a two-step route, first deposition at room temperature and then post-deposition annealing at 450 ℃, to better control the crystallization behavior. Various transmission electron microscopy (TEM) methods were employed to investigate three sets of multi-layered films with different deposition time, 10, 20, and 30 min, with especial emphasis on the effect of layered W-doping scheme on the formation of multiple VO2(B) layers. Spatial-resolved energy dispersive X-ray spectroscopy (EDS) revealed the alternative patterns of W-rich layers and W-poor layers, while the thinner films exhibited better crystallinity and texturing. By comparison with an as-deposited film, it was found that the inter-diffusion between the two types of layers was completed in the deposition step while both remained in amorphous structure. A stable W solution of about 8 cat% in VO2(B) layers measured from all these films indicated that the layered doping can tailor the multi-layered microstructure to optimize the performance of VO2(B) films.展开更多
基金This work was financially supported by the National Natural Science Foundation of China under Grant Nos. 51532006 and 51325203, Shanghai Municipal Science and Technology Commission of Shanghai Municipality under Grant No. 16DZ2260600, and the 111 Project (D16002). We are grateful to the Shanghai Institute of Ceramics for technical assistance in TEM and SEM experiments, as well as to Prof. R. Huang of East China Normal University for TEM specimen preparations
文摘To achieve a better material for uncooled infrared (IR) detector, polycrystalline VO2(B) thin films with layered W-doping were fabricated on Si substrates by magnetron sputtering, and the best temperature coefficient of resistance (TCR) value reached -4.1%/K. The film synthesis was in a two-step route, first deposition at room temperature and then post-deposition annealing at 450 ℃, to better control the crystallization behavior. Various transmission electron microscopy (TEM) methods were employed to investigate three sets of multi-layered films with different deposition time, 10, 20, and 30 min, with especial emphasis on the effect of layered W-doping scheme on the formation of multiple VO2(B) layers. Spatial-resolved energy dispersive X-ray spectroscopy (EDS) revealed the alternative patterns of W-rich layers and W-poor layers, while the thinner films exhibited better crystallinity and texturing. By comparison with an as-deposited film, it was found that the inter-diffusion between the two types of layers was completed in the deposition step while both remained in amorphous structure. A stable W solution of about 8 cat% in VO2(B) layers measured from all these films indicated that the layered doping can tailor the multi-layered microstructure to optimize the performance of VO2(B) films.
