Philippine E-Journals

Spatial Distribution and Characterization of Zinc Sulfide (ZnS) Nanostructures Prepared by Unseeded Horizontal Vapor Phase Crystal Growth (HVPCG)

Kiveen P. Suycano | Gil Nonato C. Santos

 

Abstract:

Zinc sulfide (ZnS) nanoparticles, jagged-edge nanorods, nanorods, nanofilaments, irregularly-shaped nanosheets, hexagonal nanosheets, nanoflakes, nanowires, nanobelts, nanostrips, nanoribbons, and nanowindmills were successfully synthesized from a minimal amount of ~35 mg ZnS powder of 99.9 % purity via Horizontal Vapor Phase Crystal Growth (HVPCG) at an 80-min ramp time. The growth temperature was varied from 600 °C-1200 °C in 200 °C increment with dwell time set to 4, 6, and 8 hours. The type of nanostructure formed was very sensitive to growth temperature, dwell time as well as quenching. Nanofilaments, nanorods and hexagonal nanosheets morphologies were abundantly produced under several growth conditions while the nanostrips, nanoribbons, jagged-edge nanorods, and nanowindmills occured only at a particular growth temperature, dwell time, and quenching. The effect of quenching on the formation of nanostructure was mostly observed at higher growth temperature and longer dwell time. EDX analyses revealed the atomic composition of the nanostructures. The ratio of Zn to S was close to 1:1. X-ray diffraction test result showed that the deposited nanomaterials with growth temperature of 1000 °C, dwell time of 4 hours and quenched at ~1.2 0 C had wurtzite or hexagonal crystal structure. Photoluminescence (PL) tests suggested the deficiency in sulfur and quantum confinement of the nanostructures grown at 1000 °C and 1200 °C for 4, 6, and 8 hours for both the quenched and unquenched set ups.