Low energy electron loss studies of cuInSe₂ surfaces

The low energy loss spectra (LELS) of clean and oxygen contaminated (111) p ‐type CuInSe 2 single crystals are reported. Losses due to interband transitions and plasmon excitations are observed. By varying the primary electron energy (100–500 eV) both surface and bulk features of the conduction bands are probed. As oxygen is adsorbed on the surface of the CuInSe 2 (at room temperature), the In and Se atoms seem to associate with themselves and with oxygen, whereas the Cu atoms do not seem to play a direct role in the oxidation process. LELS Spectra are presented as a function of primary beam energy and oxygen absorption.