XPS analysis on the surface of CdZnTe Annealed in Ar and H₂ atmosphere

CZT crystals were annealed in Ar and H₂ atmosphere under the same temperature conditions. XPS analysis with sputter depth profiling was employed to analyze the surface composition and valence states after annealing. Based on the above results, the possible surface structure and composition of CZT crystals were determined before and after annealing. In contrast to the Ar atmosphere annealing, TeO₂ and Te-rich layer had a significant reduction owing to chemical reaction with H₂ during the H₂ atmosphere annealing. Because of the elimination of TeO₂ and Te-rich layer, the contact area between H and CZT was increased to promote further reaction of H with CZT.