Reactively magnetron sputtered Bi₂O₃ thin films: Analysis of structure, optoelectronic, interface, and photovoltaic properties

Abstract

Bi2O3 thin films deposited by RF magnetron sputtering have been studied in situ by using photoelectron spectroscopy. UV/VIS transmission spectroscopy and XRD measurements were carried out to determine the optical and structural properties of the films. Thin film solar cells were built up with ITO|Bi2O3|Au layer structures. These devices were characterized by current–voltage and capacitance–frequency measurements. Open‐circuit voltages up to 680 mV and short‐circuit current densities of about 0.3 mA cm−2 were observed. In addition, relative permittivities of approximately 45 have been measured. In order to determine the energy band alignment of Bi2O3 with different contact materials, interface experiments were carried out. With stepwise depositions of the contact material combined with in situ observation of the Fermi level shift via X‐ray photoelectron spectroscopy, it is possible to measure the energy barrier height between a semiconductor and a metallic contact. The work functions of the different materials were determined by UV photoelectron spectroscopy.

Structural and Optical Properties of Nanostructured Bismuth Oxide

“…From this drawing, the optical energy gap Eg = 2.5 eV is deduced and this value is close to the previously reported value [20,21]. One can notice that This energy gap is rather large for a photovoltaic cell, but should be ideal for photocatalytic water splitting [15]. …”

Synthesis of Bi2O3/TiO2 nanostructured films for photocatalytic applications

“…For thicker and more crystalline TiO 2 films the E g value would approximate the bulk value. Conversely, the E g value for the Bi 2 O 3 layer is similar to what has been reported in the literature Bi 2 O 3 films with direct band-gap, between 2.8 and 2.9 eV [21,27,31]. Due to the coupling effect of the two semiconductors that reduce the optical band-gap, there is an enhancement in the photocatalytic efficiency, as observed in Fig.…”

Pure CuBi2O4 Photoelectrodes with Increased Stability by Rapid Thermal Processing of Bi2O3/CuO Grown by Pulsed Laser Deposition

“…Bi 2 O 3 is a wide‐bandgap semiconductor with E g that can range from 2.4 to 3.96 eV, depending on its phase and the preparation method. [ 12,47,48 ] The origin of the feature at 3.1 eV is beyond the scope of this study and will be addressed in a separate publication.…”