Electrooptical properties of InP epitaxial layers grown with rare-earth admixture

The influence of rare-earth (RE) elements (Ho, Er and Nd) addition during the LPE growth, on electrooptical properties of InP layers is reported. Temperature dependent Hall effect and capacitance-voltage curves show quite a dramatic impact of Er and Nd on shallow impurity and free-carrier concentrations: they were decreased by as much as three orders of magnitude. The background concentration of both donors and accepters decrease with increasing of RE content in the melt up to concentrations of about 0.25 wt.%. Low-temperature photoluminescence (PL) spectra have been measured for various levels of excitation power and temperature. The major manifestation of the RE admixture is the pronounced narrowing of PL curves and the corresponding appearence of fine spectral features. Temperature and excitation dependences of shallow acceptor related bands of InP:Nd layers are discussed in more detail.