Resonant photoionization absorption spectra of spherical quantum dots

Abstract

We study theoretically the mid-infrared photon absorption spectra dueto bound–free transitions of electrons in individual spherical quantumdots. It is established that change of the dot size in one or two atomiclayers or/and number of electrons by one or two can change the peakvalue of the absorption spectra in orders of magnitude and energy ofabsorbed photons by tens of millielectronvolts. The reason for this is theformation of specific free states, called resonance states. Numerical calculationsare performed for quantum dots (QDs) with radius varying up to 200Å, and one to eight electrons occupying the two lowest bound states. Itis supposed that realistic QD systems with resonance states would beof much advantage to design novel infrared QD photo-detectors.