Xinkun Li, Peng Jin*, Qi An, Zuocai Wang, Xueqin Lv, Heng Wei, Jian Wu, Ju Wu and Zhanguo Wang
* Corresponding author: Peng Jin pengjin@semi.ac.cn
Nanoscale Research Letters 2011, 6:625 doi:10.1186/1556-276X-6-625