Fabrication of ZnS/diamond-like carbon heterostructure nanowires

Seung Min Yu1 ,Hyeon Ih Ryu1, Hee-Suk Chung1, Tae-Sung Bae1

1Korea Basic Science Institute, Jeonju, Jeonbuk, Republic of Korea, 54907

E-mail: hschung13@kbsi.re.kr

The stability of nanomaterials is a crucial key factor corresponding to their practical applications. To fully exploit ZnS nanowires as nanodevices, waveguides, and so on, in the future, the oxidation difficulty should be first overcome. It is very important to passivate the surface of the ZnS nanowires since nanoscale ZnS structures exhibit high-chemical reactivity with respect to the deformation, oxidation, corrosion, and contamination of these structures. In this regard, several groups studied on the protection of ZnS nanowires with boron nitride (BN) or silicon dioxide (SiO2).

In this research, ZnS/diamond-like carbon core-shell heterostructure nanowires were fabricated by vapor-liquid-solid method and radio frequency plasma enhanced chemical vapor deposition. Au catalyzed ZnS nanowires have widths of 70-80nm and the thickness of outer diamond-like carbon layer was in a range of 20-30nm. The products were analyzed through extensive electron microscopy combined with chemical composition investigation. In addition, the coated DLC layer was examined by Raman spectroscopy. Two Raman bands was found at 1550 cm-1(Gpeak) and at 1330cm-1 (Dpeak), which shows typical hydrogenated diamond-like amorphous carbon. Through IR transmittance experiment, The IR transmittance of ZnS and ZnS/DLC nanowires was measured with a value of 90~98%. The enhanced IR transmittance from ZnS/DLC nanowire is only observed at 2100cm-1and 3000cm-1 with a value of 1~1.4% higher than ZnS nanowires.

Keyword: zinc sulfide nanowire, diamond-like carbon, growth mechanism, heterostructure