Thermopower and conductivity have been investigated in a series of P-doped amorphous silicon prepared by the DC glow discharge decomposition of silane of 300℃. In the case of heavily doped samples the activation energy of the thermopower is smaller than that of the conductivity by $\sym$0.15ev. It shows that the conduction doesn't take place in the extended states and the mobility is activated.
The kinks are observed in the conductivity and the thermo-power around 420K as expected. There are the downward kinks in the undoped samples and the upward kinks in the heavily doped. The observed change of the conductivity activation energy is 0.08-0.18eV for the heavily doped samples.
