Identification of the Fe acceptor level in Ga0.47In0.53As

The authors give an unambiguous identification of the Fe acceptor level in Ga 0.47 In 0.53 As and a coherent description of its electrical and optical properties by photoluminescence, thermal and photocapacitance spectroscopies. Deep-level transient spectroscopy measurements show a deep trap at E c -0.34 eV which they identify as due to the single acceptor level Fe 3+ /Fe 2+ . This is confirmed by the observation of the internal luminescence transition of Fe 2+ ( 5 T 2 to 5 E) detected at 0.35 eV and by a well pronounced resonance peak at 0.34 eV due to the transition to the 5 T 2 excited state in the sigma n 0 (h nu ) spectrum of the photoionisation cross section of the E c -0.34 eV level. Finally they discuss the validity of the empirical rule connecting transition metal levels to predict the band-gap discontinuity in the InP/InGaAs systems using the known positions of the Fe acceptor level in InP and in Ga 0.47 In 0.53 As.