Lead-free Perovskites: Toward an Opto-Electronics based on Abundant Elements and Low Temperature Synthesis

The depletion of natural resources today necessitates a reevaluation of technological development, considering both material abundance and energy-efficient processes while maintaining device efficiency. This research presents a comprehensive investigation into the design and synthesis of advanced thin films materials for improved optoelectronic applications. By exploring the unique properties of lead-free perovskites oxides, we aimed at engineering materials with enhanced electrical conductivity, stability, and optical properties.<br/>For this work, we chose two types of perovskites oxides: SrSnO₃ and LaVO₃. The reason behind this choice is the combination of abundancy, non-toxicity, and low-cost production of these materials along with the tunable bandgap, the stability and durability.<br/>In this study, we will detail the tailored synthesis process with sol-gel method using different percentages of doping. We discuss the systematic characterization of the resulting thin films through various analytical tools.<br/>Nontoxic, relatively cheap precursors, and solvents were used without generating waste materials. The viscosities were controlled, and the resulting resins were spin-coated on Silicon and Quartz. The wet films were then annealed at 673 K to remove organic material and crystallized at 1173 K for 1h in air<b>. </b>Using scanning electron microscopy, the film thickness was found to be around 200nm with a highly uniform and homogeneous surface, X-ray diffraction confirmed the perovskite phase with an intense peak at 32°, and optical measurements proved the transparency of 80% in the visible range with an absorption in the UV range around 300nm.<br/>The results reveal a clear correlation between the synthesis parameters and the optoelectronic performance of the materials, demonstrating the feasibility of optimizing these materials characteristics through precise control of the synthesis process.<br/>The objective of this work is the realization of optoelectronic components (pn junction) based on doped perovskite oxide semiconductors (SrSnO₃: Sb@SrSnO₃: Al on ITO and LaVO₃) synthesized using an ecofriendly environmental synthesis (sol-gel process). Application as light absorbers or barrier layers in highly efficient solar cells are foreseen. Other applications are also possible (e.g., LEDs).<br/>This work contributes to the ongoing efforts to develop sustainable and efficient materials for optoelectronic devices and underscores the pivotal role of advanced material synthesis techniques in achieving this goal.