A Novel Method for Notable Reducing Phase Transition Temperature of VO2 Films for Smart Energy Efficient Windows
A Novel Method for Notable Reducing Phase Transition Temperature of VO2 Films for Smart Energy Efficient Windows
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DOI：
10.3390/nano10010058
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发表时间：
2020-01-01
期刊：
影响因子：
5.3
通讯作者：
Fan, Ping
中科院分区：
文献类型：
--
作者：
Guan, Huan;Zhang, Dongping;Fan, Ping
虽然二氧化钒（VO2）由于其独特的相变特性在智能节能窗方面具有潜在的应用价值，但仍有许多障碍需要克服。其中一个挑战是将其高转变温度（zeta(c) = 68℃）降低到接近室温而不导致其相变性能下降。本文采用一种新颖的方法，在纯VO2薄膜上覆盖一层3nm的超薄重cr掺杂VO2层。与原位纯VO2相比，相变温度从59.5℃明显降低到48.0℃。与以往的掺杂技术不同，几乎没有发生相变性能的减弱。根据微观结构和电学参数测试结果，探讨了zeta(c)的还原机理。上层超薄重cr掺杂层可能起到相变诱导作用。随着温度的升高，载流子浓度从上层重cr掺杂层扩散到底层纯VO2层，并诱导载流子浓度从上到下逐渐达到相变临界值。该方法不仅技术简单，而且避免了昂贵的合金靶材。
Although Vanadium dioxide (VO2) has a potential application value for smart energy efficient windows because of its unique phase transition characteristic, there are still many obstacles that need to be overcome. One challenge is to reduce its high transition temperature (zeta(c) = 68 degrees C) to near room temperature without causing its phase transition performance degradation. In this paper, a novel method was employed that covered a 3 nm ultra-thin heavy Cr-doped VO2 layer on the pure VO2 films. Compared with the as-grown pure VO2, obviously, phase transition temperature decreasing from 59.5 degrees C to 48.0 degrees C was observed. Different from previous doping techniques, almost no phase transition performance weakening occurred. Based on the microstructure and electrical parameters measurement results, the mechanism of zeta(c) reducing was discussed. The upper ultra-thin heavy Cr-doped layer may act as the induced role of phase transition. With temperature increasing, carrier concentration increased from the upper heavy Cr-doped layer to the bottom pure VO2 layer by diffusion, and induced the carrier concentration reach to phase transition critical value from top to bottom gradually. The present method is not only a simpler technique, but also avoids expensive alloy targets.