Leo supra 35vp smt

Powder X-ray diffraction (PXRD) experiments were performed in transmission
mode using a calibrated STOE STADI-P powder diffractometer with Cu
Kα₁ radiation. The surface and cross-section morphology
of the photocathodes was characterized by scanning electron microscopy
(SEM, Leo Supra 35VP SMT, Zeiss). A spectrophotometer (Shimadzu, UV-2600)
was employed to evaluate the optical property of as-obtained thin
films. X-ray photoelectron spectrometry (XPS, Prevac) equipped with
a hemispherical analyzer (VG SCIENTA R3000) was used to verify the
surface composition. The spectra were recorded with a monochromatized
aluminum source Al Kα (E = 1486.6 eV) and calibrated
using the Au 4f_7/2 line of a cleaned gold sample at 84.0
eV.

Powder
XRD patterns were
recorded in transmission mode on a STOE STADI-P diffractometer (Cu
Kα₁ radiation) operating with a DECTRIS Mythen 1K
detector at a scan rate of 2° min^–1 in the
2θ range from 10° to 90°.
SEM images were recorded
on a Leo Supra 35VP SMT (Zeiss) thermal field emission scanning electron
microscope operating at an accelerating voltage of 10.0 kV.
TEM images were recorded on a Themis Z TEM (Thermo Fisher), and
a SuperX energy-dispersive X-ray (EDX) detector operating at 300 kV
in the scanning TEM mode was used for elemental mapping.
XPS
spectra were recorded by a hemispherical VG SCIENTA R3000 analyzer
using a monochromatized aluminum source Al Kα (E = 1486.6 eV) at constant pass energy of 100 eV. The binding energies
were referenced to the Au 4f core level (E_b = 84.0 eV). The composition and chemical surrounding of the sample
surface were determined on the basis of the areas and binding energies
of Na 1s, K 2p, P 2p, O 1s, N 1s, C 1s, and Bi 4f photoelectron peaks.
The fitting of the high-resolution spectra was obtained through the
Casa XPS software.
Ultraviolet–visible (UV–vis)
spectroscopy was performed
on a Shimadzu UV-2600 spectrophotometer. Measurements were recorded
in absorbance mode. The Tauc plots were calculated by the Kubelka–Munk
function F(R) = (1 – R)²/2R for determination of
the electronic band gap.