Positron annihilation study on vacancy-type defects in MBE-grown GaCrN films

Yabuuchi, Atsushi; Maekawa, Masaki; Hasegawa, Shigehiko*; Asahi, Hajime*; Kawasuso, Atsuo

In the crystalline growth of the GaCrN dilute magnetic semiconductor, the growth is carried out in a relatively low temperature to increase Cr concentration. However, it is expected that vacancy-type defects are introduced into the low temperature growth films. It is considered that the magnetized state of the dilute magnetic semiconductor is influenced from the existence of the vacancy-type defects. Thus, it is important to understand the relation between the growth conditions and the vacancy-type defects concentration. In the present study, we investigated the growth temperature dependency and the effect of Si doping on vacancy-type defects introduction in MBE-grown GaCrN films. The result of our experiment suggested that the vacancy-type defect exists in low temperature growth GaCrN film. Furthermore, the defect concentration was decreased with Si doping.