Ar和H_2气氛退火CdZnTe表面的XPS研究

XPS Analysis on the Surface of CdZnTe Annealed in Ar and H_2 Atmosphere

对CZT晶体进行了相同温度条件下Ar和H2气氛退火实验研究。利用XPS的离子溅射深度剖析对比分析了退火前和不同气氛退火后CZT晶体表面成分和价态的变化,并以上述变化为依据,推测了退火前CZT晶体的表面结构和成分以及退火过程中气体与CZT晶体表面发生的化学反应。结果表明,相比Ar气氛退火,H2气氛退火后因为TeO2和富Te层会先后和H2发生化学反应而大量减少,可以有效地去除TeO2和富Te层,增大H与CZT的接触面积,促进H与CZT的进一步反应。

CZT crystals were annealed in Ar and H2 atmosphere under the same temperature conditions.XPS analysis with sputter depth profiling was employed to analyze the surface composition and valence states after annealing. Based on the above results,the possible surface structure and composition of CZT crystals were determined before and after annealing. In contrast to the Ar atmosphere annealing,TeO2 and Te-rich layer had a significant reduction owing to chemical reaction with H2 during the H2 atmosphere annealing. Because of the elimination of TeO2 and Te-rich layer,the contact area between H and CZT was increased to promote further reaction of H with CZT.