Studies of Excited States for Shallow Donors in Magnetic Field on Bulk n-InP

Abstract

Through far-infrared (FIR) magneto-optical absorption measurements we have investigated excited states of shallow donors in bulk n-InP at 4.2 K. By utilizing advantage of thick bulk samples we have observed transitions from 1s ground state of donors to various excited states as 2 p +1 , 3 p +1 and 3 d +1 and a series of oscillatory absorptions caused by transitions to magnetically-induced states. By the optical saturation effect it is found that comparatively weak absorptions as the oscillatory ones become prominent due to suppression of strong absorptions. In order to make clear the excited states of donors under a magnetic field signals due to the 1s–3 p +1 and 1s–3 d +1 transitions are extremely helpful, since the resonance positions and the peak heights include various informations for excited states. Based on variation of the oscillation peaks with increases in donor concentration, we conclude that the oscillatory absorptions originate in transitions from the 1s ground state to impurity bands.