State;
Key;
Laboratory;
on;
Integrated;
Optoelectronics,;
Institute;
of;
Semiconductors,;
Chinese;
Academy;
of;
Sciences,;
Beijing;
100083,;
China;
Institute;
of;
Information;
Function;
Materials,;
Hebei;
University;
of;
Technology,;
Tianjin;
300130,;
China;
Suzhou;
Institute;
of;
Nano-tech;
and;
Nano-bionics,;
Chinese;
Academy;
of;
Sciences,;
Suzhou;
215125,;
China;
Si(111)衬底; 外延生长; 氮化镓; 缓冲层; 外延层; 氮化铝; 结构特性; 厚度;