Bi_(2)Te_(3)films are grown on(111)-oriented GaAs substrates by using the hot wall epitaxy method and the surface oxidation properties in the films are investigated by x-ray photoelectron spectroscopy,Raman spectroscopy,and x-ray diffraction.The results show that the films are c-axis oriented.Two pairs of new peaks in the XPS spectra involved with the binding energies from Bi 4f and Te 3d electrons correspond to Bi–O–Te bonds.Besides the A^(1)_(1)g,E^(2)g and A^(2)_(1)g vibration modes from Bi_(2)Te_(3)films,two new peaks at 93.5 cm^(-1)and 123 cm^(-1)are observed in Raman spectra,which are assigned toα-Bi2O_(3)and TeO_(2),respectively.Our results are helpful for analyzing the degradation mechanism of topological surface states in Bi_(2)Te_(3).
GUO Jian-HuaQIU FengZHANG YunDENG Hui-YongHU Gu-JinLI Xiao-NanYU Guo-LinDAI Ning
