物理化学学报 >> 1999, Vol. 15 >> Issue (06): 528-532.doi: 10.3866/PKU.WHXB19990609

研究论文 上一篇    下一篇

GaAs(100)解理面的能带弯曲

邓宗武, 郭伟民, 刘焕明, 曹立礼   

  1. 清华大学化学系,北京 100084|香港中文大学化学系;香港中文大学物理系
  • 收稿日期:1998-09-30 修回日期:1998-12-23 发布日期:1999-06-15
  • 通讯作者: 曹立礼

Band Bending of Cleaved GaAs(100) Surface

Deng Zong-Wu, Guo Wei-Min, Liu Huan-Ming, Cao Li-Li   

  1. Department of Chemistry,Tsinghua University,Beijing 100084;Department of Chemistry,The Chinese University of HongKong|Department of Physics,The Chinese University of HongKong
  • Received:1998-09-30 Revised:1998-12-23 Published:1999-06-15
  • Contact: Cao Li-Li

摘要:

在真空中解理后,用XPS测得了GaAs样品(110)断面能带弯曲的动态过程.两组重掺杂n型和p型GaAs样品的费米能级分别向禁带中间的方向移动了0.4eV和0.3eV. 实验测得重掺杂n型和p型GaAs样品费米能级之差为1.3eV,它们的禁带宽度理论值为1.42eV,这说明结果是合理的.根据实验结果,对引起GaAs表面能带弯曲的可能原因进行了分析讨论.排除了本征表面态、真空中残留气体和X射线辐射等原因,认为解理过程在表面产生的缺陷和解理后表面晶格弛豫过程中产生的缺陷可能是导致能带弯曲的主要原因.

关键词: GaAs, 能带弯曲, 动态过程, XPS

Abstract:

After cleaved in UHV, the dynamic band bending of GaAs(110) surface was investigated using in situ XPS measurement. It was found that the Fermi level of heavy doped n-GaAs and p-GaAs shifted to the midgap 0. 4 eV and 0. 3 eV, respectively. Fermi level difference of 1. 3eV between heavy doped n-GaAs and p-GaAs was revealed. In fact, the theoretical band gap of GaAs is 1. 42 eV, which suggests that our experimental results should be believable. Based on the experimental results, it was concluded that the surface band bending was caused neither by intrinsic surface states in GaAs, the residual gas in UHV, nor the X-ray radiation. The band bending should be caused mainly by the surface defects induced during the cleavage and more probably during lattice relaxation.

Key words: GaAs, Bnd bending, Dynamic process, XPS