Ordered Zinc Antimonate Nanoisland Attachment and Morphology Control of ZnO Nanobelts by Sb Doping

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• 作者：Baochang Cheng ; Baixiang Tian ; Wei Sun ; Yanhe Xiao ; Shuijin Lei ; Zhanguo Wang
• 刊名：Journal of Physical Chemistry C
• 出版年：2009
• 出版时间：June 4, 2009
• 年：2009
• 卷：113
• 期：22
• 页码：9638-9643
• 全文大小：389K
• 年卷期：v.113,no.22(June 4, 2009)
• ISSN：1932-7455

文摘

Hierarchical heterostructures of zinc antimonate nanoislands on ZnO nanobelts were prepared by simple annealing of the polymeric precursor. Sb can promote the growth of ZnO nanobelts along the [552] direction because of the segregation of Sb dopants on the +(001) and (110) surfaces of ZnO nanobelts. Furthermore, the ordered nanoislands of toothlike ZnSb₂O₆ along the [001]_ZnO direction and rodlike Zn₇Sb₂O₁₂ along the [110]_ZnO direction can be formed because of the match relation of the lattice and polar charges between ZnO and zinc antimonate. The incorporation of Sb in a ZnO lattice induces composition fluctuation, and the growth of zinc antimonate nanoislands on nanobelt sides induces interface fluctuation, resulting in dominance of the bound exciton transition in the room temperature near-band-edge (NBE) emission at relatively low excitation intensity. At high excitation intensity, however, Auger recombination makes photogenerated electrons release phonon and relax from the conduction band to the trap states, causing the NBE emission to gradually saturate and redshift with increasing excitation intensity. The green emission more reasonably originates from the recombination of electrons in shallow traps with doubly charged V_O^**oxygen vacancies. Because a V_O^** center can trap a photoactivated electron and change to a singly charged oxygen vacancy V_O^* state, its emission intensity exhibits a maximum with increasing excitation intensity.