Growth of ultra‐high purity PbI₂ single crystal: (1) Preparation of high purity PbI₂

Abstract

In order to prepare high purity lead iodide (PbI 2 ) single crystals, the starting material-iodine (I) has been purified by the sublimation method, and the PbI 2 polycrystalline by the normal freezing method. The purification effect of these methods has been confirmed by evaluating the impurity concentration in ingot by glow discharge mass spectrometry (GDMS) analysis. By comparing the purity of three different starting materials, non-purified iodine+6N-Pb, purified iodine+6N-Pb and commercial 6N-PbI 2 , PbI 2 synthesized by purified iodine in the present experiment has the highest purity. This indicates that these purification methods are suitable. The present research results are expected to prepare high-resistivity PbI 2 used in radiation detector.

Growth of PBI2 single crystals from stoichiometric and Pb excess melts

“…After the quartz tube was shaped by H 2 -O 2 flame, the shaped ampoule was vacuum-baked at 1373 K for 20 h. We have proved that the commercially available PbI 2 is unsuitable for growing high-purity crystal [4]. In the present study, the purified PbI 2 polycrystal is used as starting material.…”

“…The radiographic properties were measured using an X-ray source from an X-ray generator made by Hamamatsu Photonics Co. Ltd. Fig. 1 represents the photographs of PbI 2 crystals grown by the vertical Bridgman method using purified PbI 2 in our laboratory [4]. Fig.…”

“…In our previous study [4], in order to prepare high-purity PbI 2 single crystals, the starting material, iodine (I), has been purified by the sublimation method, and the PbI 2 polycrystal has been purified by the normal freezing method. The purification effect of these methods has been confirmed by evaluating the impurity concentration in the ingot by glow discharge mass spectrometry (GDMS) analysis.…”

Influence of doping and non-stoichiometry on the quality of lead iodide for use in X-ray detection

“…8-10. Low temperature PL spectra of the measured samples are characterized by two bands [4,5,10,14,15]. The high energy band at 496 nm (labeled BE) is due to excitonic recombination and the broader band (labeled D-A) at 510 nm is assigned to shallow donor related transitions, such as donor-acceptor pair recombinations.…”

“…Preparation of high quality and low defect lead iodide (PbI 2 ) single crystals for use in roomtemperature nuclear radiation detectors has been reported [1][2][3][4][5][6][7][8]. PbI 2 is a promising wide band gap material (2.32 and 2.55 eV at 4 K) with high atomic numbers of its constituents (Z Pb =82, Z I =53), low vapor pressure, high chemical stability and does not undergo structural transitions up to its melting point, T m ( $ 410 1C).…”