Studies on Fabrication of Ag/Tl2Ba2Ca2Cu3O10/CdSe Heterostructures with Electrochemical Technique

Abstract

Metal/superconductor/semiconductor (Ag/TlBaCaCuO/CdSe) heterostructures have been successfully fabricated using pulse-electrodeposition technique. The electrochemical parameters are optimized and diffusion free growth of CdSe onto Ag/TlBaCaCuO was obtained by employing under-potential deposition and by studying nucleation and growth mechanism during deposition. The heterostructures are characterized by X-ray diffraction (XRD), full-width at half-maximum (FWHM), scanning electron microscopy (SEM) studies and low temperature four probe electrical resistivity measurements. After the deposition of CdSe the critical transition temperature of TlBaCaCuO films was found be increased from 116.5 K with Jc = 2.1 x 103 A/cm2 to 118.7 K with Jc = 2.3 x 103 A/cm2. When the heterostructure was irradiated with red He-Ne laser (2 mW), the Tc was further enhanced to 121 K with Jc = 3 x 103 A/cm2. This increase in superconducting parameters of TlBaCaCuO in Ag/TlBaCaCuO/CdSe heterostructure has been explained at length in this paper. Keywords. Electrodeposition; Tl-based cuprate; semiconductor; heterostructures; electrical properties. PACS Nos 81.15.Pq; 74.72.Gr; 78.40.Fy; 84.37; 73.40 *E-mail: [e-mail], [e-mail]