Large Diameter Zinc Selenide (ZnSe) Single Crystals for Radiation Detectors

Tellurium-doped single-crystal ZnSe, or ZnSe(Te), is an important material for fabricating the radiation detectors needed for nuclear physics research. To date, there is no efficient crystal growth technique for producing high-quality, large-diameter, ZnSe single crystals. This project will investigate a novel high-temperature, physical-vapor-transport (HT-PVT) technique to grow large diameter, high quality ZnSe single crystals. These ZnSe single crystals can be used as substrates for fabricating high performance radiation detectors. Phase I will focus on exploring HT-PVT growth conditions for ZnSe single crystals, so that a growth rate of at least 0.5mm/hr can be achieved. Purity analysis, defect characterization, and electrical characterization will be performed on HT-PVT grown ZnSe single crystals. An HT-PVT growth process for ZnSe crystal boules (of 1 inch in diameter and 10 mm in length) will be established. Commercial Applications And Other Benefits as described by the Applicant: ZnSe single crystal would be an efficient scintillator material for x-ray radiation detectors and imaging devices. These radiation detectors have important applications in high energy and nuclear physics, as well as in commercial areas such as security screening, medical x-ray imaging, dental imaging, and industrial x-ray imaging. In addition, the material could be used in ZnSe-based II-VI compound semiconductor devices, such as blue and white LEDs, and blue lasers.