High‐resolution transmission electron microscopy of structural changes at and near surfaces of ZnTe crystals

Autor: M. Avalos‐Borja, X. G. Ning, Hengqiang Ye
Rok vydání: 1996
Předmět:
Zdroj: Journal of Applied Physics. 79:125-128
ISSN: 1089-7550
0021-8979
DOI: 10.1063/1.360919
Popis: Structural changes on and near surfaces of ZnTe crystals were observed by the surface profile imaging method in a high‐resolution transmission electron microscope (HRTEM) with 200 kV accelerating voltage. It was found that ZnO particles form under electron irradiation on surfaces originally covered with a thin amorphous layer. For amorphous coverages thicker than about 7 nm, ZnO particles were not observed. Under the ZnO particles, 2×1 and 2×2 superstructures (about 10 nm in size) were often found in the ZnTe matrix. These superstructures can be described as a metastable Zn2Te3 having a structure similar to the ordered Ga2Te3 structure. This change can be accomplished by considering the diffusion of zinc from the ZnTe matrix to the surface to form the oxide and evaporation of tellurium out of the surface, leaving behind a matrix with an altered stoichiometry. The HRTEM computer‐simulated images for the proposed Zn2Te3 superstructure matched very well the experimental images. The 2×1 and 2×2 superstructure...
Databáze: OpenAIRE