Trace impurities analysis determined by neutron activation in the PbI2 crystal semiconductor

In this work, a methodology for impurity analysis of PbI2 was studied to investigate the effectiveness of the purification. Commercial salts were purified by the multi passes zone refining and grown by the Bridgman method. To evaluate the purification efficiency, samples from the bottom, middle and upper sections of the ZR ingot were analyzed after 200, 300 and 500 purification passes, by measurements of the impurity concentrations, using the neutron activation analysis (NAA) technique. There was a significant reduction of the impurities according to the purification numbers. The reduction efficiency was different for each element, namely: Au>Mn>Co∼Ag>K∼Br. The impurity concentration of the crystals grown after 200, 300 and 500 passes and the PbI2 starting material were analyzed by NAA and plasma optical emission spectroscopy.