State;
Key;
Laboratory;
of;
Materials;
Modification;
by;
Laser,;
Ion;
and;
Electron;
Beams,;
School;
of;
Physics;
&;
Optoelectronic;
Engineering,;
Dalian;
University;
of;
Technology,;
Dalian;
116024,;
China;
Department;
of;
Molecular;
Science;
and;
Technology,;
Ajou;
University,;
San;
5;
Wonchon-Dong,;
Youngtong-Gu,;
Suwon;
443-749,;
Korea;