采用X射线光电子能谱对Bi_2Sr_2CaCu_(2-x)Li_x,Oy体系在真空中获得的清洁表面进行了研究。结果表明:Li的掺入对Bi和Sr的化学键性质几乎没有影响,而Ca,Cu,O的化学键性质有较大的变化,其结合能随着Li含量x的增加向高能方向移动。同时对真空中获得的清洁表面和普通表面样品O_(1s)进行了比较,结果发现真空中获得的清洁样品O_(1s)有一个峰(528.4eV),而普通表面样品O_(1s)有两个峰(528.4eV)和(531eV),这表明O_(1s)的高能峰是由污染产生的。 The clean surface of Bi_2Sr_2CaCu_ (2-x) Li_x, Oy system in vacuum was studied by X-ray photoelectron spectroscopy. The results show that the incorporation of Li has almost no effect on the chemical bond properties of Bi and Sr, while the chemical bond properties of Ca, Cu and O have great changes. The binding energies of Li and Li increase with the increase of Li content to high energy direction. At the same time, the clean surface O_ (1s) obtained in vacuum was compared with that of normal surface O_ (1s). The results showed that there was a peak (528.4eV) in O_ (1s) The peaks (528.4 eV) and (531 eV) indicate that the high energy peak of O 1s is caused by the pollution.