FERROELECTRIC METAL-OXIDES FOR PHOTOVOLTAIC DEVICES

Recently, ferroelectric materials have attained significant interest as candidates for photovoltaic devices. These materials exhibit a unique property – the ability to remain polarized after the application of an external electric field. This property has been reported to allow an internal electric field that drives charge separation within a single material, as opposed to p-n heterojunction, where the field is formed in the junction between two materials.

Spray pyrolysis is a versatile technique for fabricating a wide range of materials. This technique is inherently low cost and highly scalable. In most cases, the system consists of an atomizer nozzle, an organometallic precursor, a hot plate, and a carrier gas. The pyrolysis step initiates when contact is formed between the organometallic solution and the hot plate. In this process the organic ligands attached to the metal ion disassemble and evaporate, and oxygen enters as a substituent, resulting in the formation of a metal-oxide thin film layer.

In this work, we use spray pyrolysis for the fabrication of ferroelectric materials based on Bismuth different compounds such as BiFeO₃, Bi₂FeCrO₆, and BiMnO₃. We present a full set of physical and chemical characterizations such as optical absorptance, phase analysis, resistivity, energetic band diagrams, and most important their photovoltaic properties. We demonstrate the photovoltaic performance both as standalone materials and in a junction configuration