Help Privacy Policy Disclaimer
  Advanced SearchBrowse




Journal Article

Photoelectron emission from heterojunctions with intralayers: band-offset changes vs. band-bending effects


Horn,  Karsten
Molecular Physics, Fritz Haber Institute, Max Planck Society;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available

Horn, K., Moreno, M., Alonso, M., Höricke, M., Hey, R., Sacedón, J. L., et al. (2002). Photoelectron emission from heterojunctions with intralayers: band-offset changes vs. band-bending effects. Vacuum, 67(1), 115-123. doi:10.1016/S0042-207X(02)00198-7.

Cite as: https://hdl.handle.net/11858/00-001M-0000-0011-13F0-3
The concept of "tuning" semiconductor heterojunction band offsets, by inserting a very thin layer of foreign atoms at the interface which acts as an "interface dipole", has received considerable attention. Modifications of the apparent valence-band offset, as measured by photoelectron spectroscopy (PES), have been indeed observed upon Si insertion at GaAs-AlAs interfaces, and have been interpreted as real band-offset changes. However, there is an alternative explanation of the results in terms of band-bending effects. Here, we present results of PES experiments designed to test these two interpretations. We have examined the effect of Si insertion at polar (1 0 0) and nonpolar (1 10) interfaces, and we have studied the insertion of Si (n-type) and Be (p-type) intralayers. Similar results are obtained for polar and nonpolar interfaces, and effects of opposite sign are observed for Si and Be intralayers. These results can be readily interpreted in terms of a band-bending profile modification upon Si or Be insertion. We analyse the implicit assumptions often made when using photoemission for band-offset determination, and the consequences of neglecting them. Photoemission experiments performed at different substrate temperatures, which make use of the surface photovoltage induced by the incident photons, permit a test of our proposed band profiles. From these data, we obtain evidence for a sample band bending, which is consistent with the room-temperature band profiles proposed. Hence, our results can be completely understood within a band-bending interpretation, without need to invoke the interpretation of intralayer action in terms of a "band-offset tuning" effect.