APPLIED PHYSICS LETTERS
SUN T, WANG ZL, SHI ZJ, RAN GZ, XU WJ, WANG ZY, LI YZ, DAI L, QIN GG
NANO LETTERS
XU JH, YIN QY, LI XR, TAN XY, LIU Q, LU X, CAO BC, YUAN XT, LI YZ, SHEN L, LU YF