Title :
Photoemission study of CdTe surfaces after low-energy ion treatments
Author :
Hanks, D. ; Weir, M. ; Horsley, K. ; Hofmann, T. ; Weinhardt, L. ; Bär, M. ; Barricklow, K. ; Kobyakov, P. ; Sampath, W. ; Heske, C.
Author_Institution :
Dept. of Chem., Univ. of Nevada, Las Vegas, NV, USA
Abstract :
We present a study of low-energy ion surface cleaning treatments and their impact on the surface electronic structure of an air-exposed CdTe thin film treated with CdCl2. In order to determine the electronic structure using surface-sensitive photoemission, surfaces need to be free of contaminants. This is achieved by subsequent low-energy ion treatment steps, carefully monitoring the chemical and electronic surface structure. We present data on the valence band maximum (VBM), and core-level binding energies, that suggest that neither preferential sputtering occurs nor metallic states are formed using our cleaning procedure. For a clean CdTe surface, the VBM is determined to be (0.8 ± 0.1) eV below the Fermi energy.
Keywords :
Fermi level; II-VI semiconductors; binding energy; cadmium compounds; core levels; photoemission; semiconductor thin films; sputter deposition; surface cleaning; surface contamination; surface structure; valence bands; wide band gap semiconductors; CdTe; Fermi energy; chemical surface structure; core-level binding energy; electronic surface structure; low-energy ion surface cleaning treatment; surface electronic structure; surface-sensitive photoemission; thin film; valence band maximum; Argon; Chemicals; Spectroscopy; Surface cleaning; Surface contamination; cadmium telluride; photoemission; surface band alignment; surface treatment;
Conference_Titel :
Photovoltaic Specialists Conference (PVSC), 2012 38th IEEE
Conference_Location :
Austin, TX
Print_ISBN :
978-1-4673-0064-3
DOI :
10.1109/PVSC.2012.6317643