Properties of InP doped with 4d ions
The authors have grown InP crystals doped with elements from the second long period (Nb, Mo, Ru, Rh and Pd) by the high-pressure gradient freeze method or by the liquid encapsulated Czochralski technique. Samples have been characterised electrically by Hall effect measurements and chemically analysed by spark source mass spectroscopy and secondary-ion mass spectrometry. They found the 4d impurities are introduced with a concentration of many 1015 cm-3. Nevertheless by spectroscopic measurements (electron paramagnetic resonance, photoluminescence and optical absorption) the authors have detected no lines which could be related to a ground or an excited state of the 4d impurity in isolated form.