fig4

Figure 4. XPS spectra of Cu₂O (100) and HY-Cu₂O (100). (A) Cu 2p spectrum of HY-Cu₂O (100); (B) Cu 2p spectrum of Cu₂O (100); (C) O 1s spectrum of HY-Cu₂O (100); (D) O 1s spectrum of Cu₂O (100); (E) S 2p spectrum of HY-Cu₂O (100); (F) S 2p spectrum of Cu₂O (100); AES of different samples: (G) Cu LMM spectrum of Cu₂O (100); (H) Cu LMM spectrum of HY-Cu₂O (100); (I) C 1s spectrum of HY-Cu₂O (100). XPS: X-ray photoelectron spectroscopy; AES: Auger electron spectroscopy; LMM: L-shell M-shell M-shell auger transition.