Growth of PbI₂ single crystal by the top seed vertical zone melting method

Abstract

PbI 2 is a type of syntectic compound, and its single crystal is one of the room temperature semiconductor nuclear radiation detector materials. A new method for the growth of the PbI 2 single crystal is proposed in this article, which was named the top seed vertical zone melting method (TSVZMM), directly from the synthesis of polycrystal with analytically pure lead and iodine, by controlling the decomposition and stratification of the melt and the stoichiometry of the PbI 2 crystal. Impurities in the crystal and the coagulating droplets of lead were eliminated during the PbI 2 crystal growth process from the top to bottom by TSVZMM. The PbI 2 single crystal was successfully grown with the size of 15 mm×15 mm, an infrared transmittance of more than 40%, a resistivity of 2×10 12 cm magnitude and stoichiometry close to its theoretical value.

Growth of lead iodide single crystals used for nuclear radiation detection of Gamma‐rays

“…The transmission rate of the two crystals reaches 50% in the range of 4000∼400 cm −1 . This value is higher than that has been reported, generally 40∼45% . Based on the solid state physics theory, the theoretical infrared transmission rate of the PbI 2 crystal can be calculated to be 58.8% .…”

“…Nevertheless, it is very difficult to grow high quality PbI 2 single crystals with low defect density, mainly because of the high vapour pressure of I 2 , easy thermal decomposition and melt stratification . Generally, the PbI 2 single crystal was tried to be grown by numerous melt methods, such as zone melting (ZM) method , traveling melting zone (TMZ) method , and vertical Bridgeman (VB) method , even Czochralski method . Vertical gradient freezing (VGF) method is a novel way to grow high quality single crystal.…”

PbI2 Nanosheets for Photodetectors via the Facile Cooling Thermal Supersaturation Solution Method

“…The low-dimensional PbI 2 nanostructures of nanosheets, nanowires, and nanobelts are well compatible with the traditional micro/nano fabrication processing and have broad application prospects. Recently, many physical and chemical approaches including melt method, , mechanical exfoliation, , and sol–gel and solution method , have been successfully used to synthesize the micro- and nano-structured PbI 2 crystals with outstanding performances. However, the high temperature applied in the melt method results in the polytype admixture and defects in crystals.…”

α-Particle Detection and Charge Transport Characteristics in the A3M2I9 Defect Perovskites (A = Cs, Rb; M = Bi, Sb)

“…On the other hand, high-purity germanium detectors offer excellent resolution, but require impractical liquid nitrogen cooling . Alternative halide-based materials such as BiI 3 , HgI 2 , PbI 2 , and TlBr have shown limited promise for room-temperature operation, but have limitations such as carrier polarization effects in TlBr or the softness of HgI 2 and PbI 2 , which inhibits device fabrication. To fully deliver on the promise of this field, new wide-gap materials are needed.…”