Growth of highly conducting epitaxial ZnO–Pt–ZnO heterostructure on α-Al2O3 (0001)

Here we report the growth of epitaxial ZnO–Pt–ZnO trilayer structures on sapphire (0001) substrate by using pulsed laser deposition technique. These structures were characterized using X-ray diffraction, conventional and high-resolution transmission electron microscopy, STEM (scanning Transmission Electron microscopy-Atomic number) Z-contrast, optical transmittance and electrical resistivity measurements. X-ray diffraction and TEM experiments revealed the epitaxial nature of these structures, the orientation relationship being: 〈111〉pt||〈0001〉ZnO||〈0001〉〈0001〉sapphire (out of plane) and 〈110〉pt||〈21¯1¯0〉ZnO||〈011¯0〉sapphire (in Plane) for the trilayer structure. Electrical and optical measurements showed that these heterostructures exhibit quite good electrical conductivity and at the same time possess moderate optical transmittance.