Synthesis and characterization of high-purity SnO2(ZnO:Sn)m superlattice nanowire arrays with broad-spectrum emissions

SnO2(ZnO:Sn)(m) is a new phase recently found in the diagram of a ZnO-SnO2 binary system in the form of a one-dimensional nanowire, which is a new group of superlattice oxide besides the widely known M2O3(ZnO)(m) (M = trivalent elements, such as In, Ga, and Al, and m = integer). Thereafter, more comprehensive structural and physical properties of SnO2(ZnO:Sn)(m) are still quite lacking due to the difficulties in high purity synthesis. In this study, we demonstrate a rational design for the growth of SnO2(ZnO:Sn)(m) superlattice nanowire arrays using a home-built double-tube chemical vapor deposition (CVD) system for the first time. The atomic microstructure of the nanowire array was investigated by Cs-corrected scanning transmission electron microscopy (STEM), and a phenomenon of unsaturated Sn occupation in Sn-O octahedral layers was observed. Two new vibrational modes at 276 cm(-1) and 698 cm(-1) were found in Raman measurement. The photoluminescence (PL) spectrum of SnO2(ZnO:Sn)(m) superlattice nanowires displays an interesting broad-spectrum emission in the range of around 380-570 nm. Kelvin probe force microscopy reveals that the average work function of SnO2(ZnO:Sn)(m) nanowires is in the range of 4.05-4.32 eV.