Gettering properties of praseodymium in GaAs, In0.53Ga0.47As, and InP grown by liquid phase epitaxy

The incorporation of praseodymium (Pr) into GaAs, In0.53Ga0.47As, and InP during liquid-phase epitaxy were investigated by double crystal x-ray; diffraction, Hall effect, low temperature photoluminescence (PL) measurements. The lattice mismatch slightly vary with Pr concentration in the growth melts. Examinations of the electrical property illustrate that the lower carriers concentrations and a higher mobilities are obtain from Pr-doped epilayers than undoped sample (In0.53Ga0.47As and InP). The PL spectra (15-K) show that the intensity of the impurity related peaks decreases and the near-band-to-band luminescence intensity increase. They also reveal that the impurities are gettered by Pr ions during LPE growth. Thus, for the purpose of purification, proper amount of Pr in the growth melts is suggested. No intra-4f-shell transition line is observed from the Pr-doped GaAs, In0.53Ga0.47As, and InP layers.