Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Synthesis and characterization of VO2-based thermochromic thin films for energy-efficient windows | Batista et al. Nanoscale Research Letters 2011 6 301 http content 6 1 301 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Synthesis and characterization of VO2-based thermochromic thin films for energy-efficient windows Carlos Batista Ricardo M Ribeiro and Vasco Teixeira Abstract Thermochromic VO2 thin films have successfully been grown on SiO2-coated float glass by reactive DC and pulsed-DC magnetron sputtering. The influence of substitutional doping of V by higher valence cations such as W Mo and Nb and respective contents on the crystal structure of VO2 is evaluated. Moreover the effectiveness of each dopant element on the reduction of the intrinsic transition temperature and infrared modulation efficiency of VO2 is discussed. In summary all the dopant elements-regardless of the concentration within the studied range-formed a solid solution with VO2 which was the only compound observed by X-ray diffractometry. Nb showed a clear detrimental effect on the crystal structure of VO2. The undoped films presented a marked thermochromic behavior specially the one prepared by pulsed-DC sputtering. The dopants effectively decreased the transition of VO2 to the proximity of room temperature. However the IR modulation efficiency is markedly affected as a consequence of the increased metallic character of the semiconducting phase. Tungsten proved to be the most effective element on the reduction of the semiconducting-metal transition temperature while Mo and Nb showed similar results with the latter being detrimental to the thermochromism. Introduction Solar control coatings are a technology of growing interest due to the necessity of improving the energy efficiency of buildings with a view to avoiding excessive energy consumption due to cooling systems during summer. The latest approach is based on the use of thermochromic coatings on the so-called smart windows. These coatings possess the ability of actively changing .
