Perovskite ferroelectric thin film as an efficient interface to enhance the photovoltaic characteristics of Si/SnO_x heterojunctions

Abstract

Ferroelectric thin layer as an interface to enhance the photovoltaic characteristics of Si/SnOx heterojunctions for building efficient ferroelectric-based solar cells.

All-Oxide p–n Junction Thermoelectric Generator Based on SnOx and ZnO Thin Films

“…The O 1s peak is deconvoluted into three peaks at 530.16 ± 0.051 eV (associated with O–Sn 2+ ), 530.80 ± 0.05 eV (associated with O–Sn 4+ ), and 532.13 ± 0.05 eV (absorbed O x ions), as shown in Figure d . The contents of SnO 2 and SnO were calculated using the Sn 3d spectra and were 48 and 52%, respectively, which suggest a p-type SnO x film . This result is also in good agreement with our previous X-ray diffraction (XRD) studies that confirmed the presence of both phases .…”

“…The decreased value for Δ E V is related to the formation of a ZnO/SnO 2 heterojunction, as Figure suggests, since the SnO x film is composed of SnO and SnO 2 . The Δ E C at the interface was also determined from the following equation , where E g SnO x and E g ZnO are the band gap values obtained experimentally for the SnO x ( E g = 2.70 eV) and ZnO ( E g = 3.37 eV) films, which agrees with the calculated ones. The Δ E C is 0.98 eV.…”

“…Although there are no diffraction rings related to the SnO phase, probably due to their small concentration, we have unequivocally identified the presence of SnO in the SnO x layer in the band alignment studies performed by XPS measurements as well as in the deconvolved Sn 3d 5/2 peaks. Furthermore, our previous XRD studies confirmed the presence of SnO and SnO 2 phases in the SnO x films. , Moreover, the energy-dispersive X-ray spectroscopy (EDS) maps (Figure c) reveal the distribution of Zn, Sn, O, and Si elements in the layers and the substrate. The color image in RGB was obtained by superposition of images of each element and no perceptible diffusion between the layers is observed.…”

“…The O 1s peak is deconvoluted into three peaks, at 530.19 eV (O 2– ions in the ZnO lattice), 531.00 eV (O 2– ions in oxygen-deficient regions within the ZnO matrix), and 532.25 eV (chemisorbed and dissociated oxygen species or OH), respectively Figure c shows the fitted Sn 3d 5/2 core-level spectrum with Sn 2+ (at 486.25 ± 0.05 eV) and Sn 4+ (at 486.90 ± 0.05 eV) components, respectively, which are in agreement with the reported values . The VB value of SnO x is determined to be 1.65 ± 0.05 eV.…”

“…TEM images of the p–n heterojunction device were obtained on a JEM-ARM 200F analytical electron microscope operated at 200 kV. The details of sample preparation can be found elsewhere . X-ray photoelectron spectroscopy (XPS) measurements were carried out using the experimental conditions that can be found in ref .…”