SQA Higher Physics Practice Exam

In semiconductors, when the temperature increases, the energy levels of the charge carriers are influenced by thermal excitation. As temperature rises, more electrons gain sufficient energy to jump from the valence band into the conduction band. This increases the number of charge carriers available for conduction, which in turn leads to an increase in conductivity. The increased thermal energy enhances the mobility of these charge carriers, allowing them to move more freely through the semiconductor material. Consequently, the overall conductivity of the semiconductor material rises with temperature, facilitating more efficient electrical conduction. This behavior is fundamental to the function of semiconductors and is utilized in various applications, such as in thermistors and temperature sensors, where the variation in conductivity with temperature is a key principle.