Light and heavy ion effects on damage clustering in GaAs quantum wells

Abstract

Recent experiments have shown that ion irradiation can strongly affect charge carrier dynamics in GaAs quantum wells. The irradiation conditions are such that the ions penetrate deep beyond the active layer, showing that the effect is due to damage in the lattice. Moreover, ions of different mass and energy can lead to clearly different effects even after normalization with the nuclear deposited energy. Using molecular dynamics simulation of the damage production, we show that the experimentally observed effects on charge carrier lifetime correlate well with the production of large (more than 100 disordered atoms) damage clusters. Moreover, we show that 400keV Ne and 10MeV Ni produce very similar damage in the near-surface active regions, indicating that 500kV ion implanters are sufficient to achieve the desired modification effects.