Definitive Identification Of The Fe3+/Fe2+ Level In Ga0.47In0.53As Layers

We give an unambiguous identification of the single acceptor level (Fe3+/Fe2+) related to iron in Ga0.47In0.53As and a coherent description of its electrical and optical properties using photoluminescence, thermal and optical capacitance spectroscopies. Investigated layers are either Fe doped or undoped and grown on semi insulating Fe doped InP or n+ substrates by LPE or MBE methods. The internal photoluminescence transition of Fe2+ (5T2-5E) is detected at 0.35eV in the ternary for the first time. Deep level transient spectroscopy measurements show one deep level at Ec-0.34eV which we identify as being caused by the Fe3+/Fe2+ acceptor level. This is confirmed by the o (hv) spectrum of the photoionization cross-section which shows a very well marked resonance peak at 0.34eV due to the transition to the 5T2, excited state. Finally, we discuss the validity of the internal referred binding energy model to predict the band discontinuity in the InP/GaInAs system using the Fe3+/Fe2+ energy level position in the two materials.