抄録
The pulsed-laser induced “ transient thermoelectric effect (TTE) \
q \
q of a quasi-two-dimensional γ-Mo4O11 crystal has been measured under a static electric field over the time range 50, ns--100, ms and temperature range 6--300, K. Upon application of static electric field, the TTE voltages are enhanced and most of these signals change their sign for reversal of the field direction, which is attributable to the change in photoinduced \lq ambipolar states'. The TTE voltages are characterized by photo-generated carrier diffusions with four relaxation times τ i (i=1-4), from which we have evaluated the carrier mobilities μ i. Using our dynamic data and existing block-band model, we have self-consistently calculated the temperature dependence of the dc transport quantities, in satisfactory agreement with the experiments. The difference in the electronic properties for γ - and its similar η -type Mo4O 11 is also discussed.