| 摘要 |
PROBLEM TO BE SOLVED: To reduce power consumption of a liquid crystal display device and suppress display deterioration, and furthermore, to suppress display deterioration due to an external factor such as temperature.SOLUTION: A transistor having a channel forming region composed of an oxide semiconductor layer is used as a transistor provided in each pixel. By increasing the purity of the oxide semiconductor layer, an off current value of the transistor at room temperature can be 10 aA/μm or less and an off current value at 85°C can be 100 aA/μm or less. Thus, power consumption of a liquid crystal display device can be reduced and display deterioration can be suppressed. Furthermore, as described above, the off current value of the transistor even at a high temperature such as 85°C can be 100 aA/μm or less. Therefore, display deterioration of the liquid crystal display device due to an external factor such as temperature can be suppressed. |
