Potential Modulation of Semiconductor Dot Array System due to Photoexcitation

Far-infrared magnetooptical absorption measurement of a quantum dot array is carried out. In contrast to the starting two-dimensional electron gas, the shift of the resonance peak of a dot array structure can be clearly observed under pulsed photoexcitation. From the delay time variation, change of the peak shift is quite slow. This peak shift does not depend simply on the change in the carrier concentration by photoexcitation. The photoexcited carrier changes the charge states around the dot. The peak shift can be interpreted by the potential modulation due to photoexcitation.