Modified Vapor Phase Growth of Cadmium Zinc Telluride: A Progress Report

We have completed a series of experiments where we realized Cd(1−x)ZnxTe by modified Vapor Phase Growth in which the CdTe and ZnTe components were separated in the growth ampoule, with their vapors passing through channels and openings designed to mix them stoichiometrically at the growth surface. We have obtained polycrystalline CZT boules 50 mm in diameter and 10 mm high whose structure is strikingly different from that obtained by standard High Pressure Bridgman methods. Our mVPG properties relevant for detector applications include resistivity of∼40 GΩ-cm when voltage is first applied, rising to ∼66 GΩ-cm after ∼20 min when the traps are filled, and electron mobility-lifetimes of∼2 × 10−3 cm2/ν. Here we present some structural and operational characterizations of our mVPG CZT.