CHARACTERIZATION OF ATOMIC LAYERS OF TELLURIUM ELECTRODEPOSITED ON THE LOW-INDEX PLANES OF GOLD

In the present study, well-ordered atomic layers of Te were formed electrochemically in aqueous solutions on the low-index planes of Au, at a variety of coverages. These layers were formed by both oxidative and reductive underpotential deposition (UPD). Sequences of structures were observed to form on each face as a function of coverage. Initial low-coverage structures consisted of ordered arrays of isolated Te atoms, while subsequent deposition resulted in the formation of ordered arrays of Te dimers. Conversion of Te monomers to dimers required 300 mV. Atomic layers of Te, formed by the reduction of excess Te0 to Te2-, also resulted in well-ordered atomic layers of Te. The pH of the deposition solution had little effect on deposit structure. Deposition of the equivalent of 50 monolayers of Te produced some degree of order on each of the low-index planes, including a clearly visible (square-root 2x square-root 5)R45-degrees on Au(100).