Selenophosphate Pb2P2Se6 Single Crystals Growth by Chemical Vapor Transport (CVT) Method for Radiation Detection

Abstract

AbstractThe heavy metal selenophosphate Pb2P2Se6 emerges as a promising room‐temperature X‐ray/γ‐ray detectors due to its high resistivity, robust radiation‐blocking capability, and outstanding carrier mobility‐lifetime product, etc. However, the high activity of phosphides poses significant impediment to the synthesis and single crystal growth. In this work, we have prepared high‐quality Pb2P2Se6 single crystals with using the chemical vapor transport (CVT) method. The XRD analysis combined with EDS result confirmed the uniform composition of the resulting as‐grown single crystals, while UV‐Vis‐NIR transmittance spectra revealed the bandgap of 1.89 eV. Selected area electron diffraction patterns indicated the crystal belonged to the P21/c(14) space group. Additionally, the Au/Pb2P2Se6/Au device is fabricated, which exhibits a robust X‐ray response with a sensitivity of 648.61 μC Gy−1 cm−2 at 400 V mm−1 under 50 kVp. Notably, the device also excels in alpha particle detection, boasting a resolution of ~14.48 % under a bias of 400 V bias. The hole mobility‐lifetime product (μτ)h of Pb2P2Se6 is estimated to be ~2.58×10−5 cm2 V−1. The results underscore potential applications of Pb2P2Se6 crystal is in the field of the semiconductor radiation detectors.