Perovskite epitaxial multiferroic BiFeO3 nanoislands were grown on SrTiO3 (100) and Nb-doped SrTiO3 (100) single crystal substrates by chemical self-assembled method. Their phase structure and morphology were characterized by X-ray diffraction, scanning electron microscopy, and atomic force microscopy, respectively. The results showed that epitaxial multiferroic BiFeO3 nanoislands were obtained via post-annealing process in the temperature range of 650 - 800°C, and their lateral sizes were in the range of 50 - 160 nm and height of 6 -12 nm. With increasing the post-annealing temperature, the morphology of BiFeO3 nanoisland in the (100) growth plane evolved from tri-angled to squared, and then to plated shapes. By using piezo-force microscopy, ferroelectric characteristics of a single epitaxial BiFeO3 nanoisland (with lateral size of ~ 50 nm and height of 12 nm) grown on Nb-doped SrTiO3 (100) single crystal substrate, was characterized. The results demonstrated that fractal ferroelectric domains existed in the single BiFeO3 nanoisland, and self-biased polarization was also observed within this multiferroic nanoisland. This phenomenon can be ascribed to the interfacial stress caused by the lattice misfit between the BiFeO3 nanoisland and the SrTiO3 single crystal substrate.

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Phosphorus-doped p-type ZnS NWs were synthesized by chemical deposition method. The as-synthesized NWs shows obvious p-type conduction with a hole concentration of 8.35 × 1017 cm-3. ZnS-Si core-shell nanoheterojunction was fabricated by depositing Si thin film on the surface of ZnS NWs through a sputtering method. The core-shell nanostructure exhibited excellent photoresponse to white light and UV light. Under UV light illumination, a high performance with a responsibility of ~ 0.14 × 103 AW-1, a gain of ~ 0.69 × 103 and a detectivity of ~ 1.2 × 1010 cmHz1/2W-1 were obtained based on the ZnS-Si core-shell nanoheterojunction. This new nanostructure is expected to play an important role in the next-generation optoelectronic devices.