Structural transition from MgZnO nanowires to ultrathin nanowalls by surface separation: growth evolution and gas sensing properties.
This paper reports a spontaneous method of controlling the growth mode from vertically arrayed ultra-slim MgZnO nanowires to nanowalls through the in-plane random motion of the seed crystals formed by surface phase separation. Seed crystals with a relatively Zn-rich phase were formed by the simultaneous injection of Mg and Zn and became strongly networked when the Zn/Mg flux ratio was increased at high temperatures, leading to the formation of MgZnO nanowalls on various conducting substrates. The hydrogen sensing performance of the MgZnO nanowalls with a two-dimensional network structure was superior to that of the one-dimensional MgZnO nanowires. Based on the microstructural characterizations, the growth procedure for the structural transition from MgZnO nanowires to nanowalls on the Si substrates was proposed.
Kim
Dong Chan
DC
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Jangan-gu, Suwon, Gyeonggi-do, Republic of Korea.
Lee
Ju Ho
JH
Mohanta
Sanjay Kumar
SK
Cho
Hyung Koun
HK
Lee
Jeong Yong
JY