Question

does conductivity of semiconductors not decrease with increase in temperature because the movement of kernals increase and resist the flow of electrons??

Answer 1

In semi- conductors, the gap between the valence band and conductor band is small and electrons can easily jump into the conductance band from the valence band. At higher temperatures, thermal excitation of the electrons allows for an increasing fraction of electrons to jump across this band gap and populate the conduction band. The semiconductor becomes more conductive as the temperature is raised.