The conduction band inside the tungsten oxide structure occupies an electronic state. Its band gap is small. If tungsten oxide is excited by the proper energy (such as thermal energy, light energy and electric energy), its valence electrons can acquire the energy and be excited into the conduction band.

Tungsten oxide charge layer structure of the surface atomic arrangement will be periodically destroyed. The tungsten oxide charge layer surface contains more dangling bonds, and each dangling bond in the tungsten oxide charge layer corresponds to a surface level.

Tungsten trioxide thin film is by far the earliest found, the most widely used, the most promising electrochromic materials. In addition to its wide range of applications in electrochromic, tungsten trioxide thin films have also found wide applications in such areas as geotropism, photochromes, filters, dye-sensitized solar cells and the like.

Tungsten trioxide has a discoloration effect. Tungsten oxide thin film in the color state of darker, the visible and infrared light in the sun has a strong absorption, can sooth the greenhouse effect, reducing the summer to reduce the power consumption for cooling. Tungsten trioxide also has an aerochromic effect. In terms of gas sensing, tungsten oxide gas sensors are widely used for the detection of flammable gases.