Composition-tuned ZnO--CdSSe core--shell nanowire arrays.
Vertically aligned ZnO--CdSSe core-shell nanocable arrays were synthesized with a controlled composition and shell thickness (10-50 nm) by the chemical vapor deposition on the pregrown ZnO nanowire arrays. They consisted of a composition-tuned single-crystalline wurtzite structure CdS1-xSex (x=0, 0.5, and 1) shell whose [0001] direction was aligned along the [0001] wire axis of the wurtzite ZnO core. The analysis of structural and optical properties shows the formation of Zn containing alloy in the interface region between the ZnO core and shell, which can facilitate the growth of single-crystalline shell layers by reducing both the lattice mismatch and the number of defect sites. In contrast, the TiO2 (rutile) nanowire array can form the polycrystalline shell under the same condition. The photoelectrochemical cell using the ZnO--CdS photoelectrode exhibits a higher photocurrent and hydrogen generation rate than that using the TiO2-CdS one. We suggest that the formation of the CdZnSSe intermediate layers contributes to the higher photoelectrochemical cell performance of the ZnO--CdSSe nanocables.
Myung
Yoon
Y
Department of Chemistry, Korea University, Jochiwon 339-700, Korea.
Jang
Dong Myung
DM
Sung
Tae Kwang
TK
Sohn
Yong Jei
YJ
Jung
Gyeong Bok
GB
Cho
Yong Jae
YJ
Kim
Han Sung
HS
Park
Jeunghee
J