Determination of ZnO(0001) surface termination by x‐ray photoelectron spectroscopy at photoemission angles of 0° and 70°

Abstract

We present an XPS method to determine the termination of the ZnO(0001) surface. By measuring O 1s and Zn 2p 3/2 core-level x-ray photoelectron spectra at photoemission angles of 0• and 70• and comparing the intensity ratio .I O1s /I Zn2p3 / q=0 /.I O1s /I Zn2p3 / q=70 , the Zn and O termination can be distinguished. Calculations show that these two terminations have intensity ratios differing by ∼17%. This difference is not affected by a contamination layer provided that the contamination layer thickness is the same for these two differently terminated surfaces. Although this determination method prefers a clean ZnO(0001) surface (in situ measurement), it seems also feasible for surfaces with known contamination layer thickness (ex situ measurement). We have measured ex situ ZnO (0001)

Electro-chemical deposition of zinc oxide nanostructures by using two electrodes

“…A second component is observed also by Pradahan et al, 23 which they associate to the zinc hydroxide, Zn(OH) 2 , and by many other authors. 24,25 The energy difference between the two components in our case is 1.4 eV, which represents a smaller value than the ones reported in literature between 1.5-2 eV. In our case it is unlikely that the component is related to the hydroxyl groups because the sample is annealed at 300…”

“…XPS spectra are shown in Fig 5. The binding energy alignment of all spectra is done by fixing the Zn2p 3/2 at 1022.5 eV according to the value found in literature. 25 The O1s spectrum of both samples clearly presents at least two components. To understand the origin of these components, the spectra are fitted using Gaussian functions.…”

Low on-resistance diamond field effect transistor with high-k ZrO2 as dielectric

“…The binding energies for them were 530.4 ± 0.2 and 532.2 ± 0.2 eV, respectively. Based on the intensity ratio of the Zr 3 d 5/2 to O 1  s and the inelastic mean free paths for them28, the atomic ratio between zirconium and oxygen can be calculated to be 1:2. Thus, we obtained the stoichiometric SD-ZrO 2 layer on the H-diamond surface.…”

Growth of zinc phthalocyanine onto ZnS film investigated by synchrotron radiation-excited X-ray photoelectron and near-edge absorption spectroscopy

“…A tunable excitation energy allows to vary the surface sensitivity of the C 1s core level spectrum, which can be taken advantage of to probe topmost carbon species with a highly surface sensitive excitation. For X-ray photoelectron spectroscopy with a conventional X-ray tube, increasing surface sensitivity is typically obtained by increasing the angle between the surface normal and the detector axis, and the angle-dependent intensity ratio of different elements was recently used to determine the surface termination of ZnO(0 0 0 1) [37]. In the case of Pc molecules the ratio of C1 and C2 species in the C 1s spectrum can be used for the determination of the orientation.…”