Synthesis of Perovskite-Structured SrTiO3 via the Pechini Method and Deposition of Thin Film by RF Magnetron Sputtering: Structural and Photovoltaic Characterization

Strontium titanate (SrTiO3) is a stable, non-toxic perovskite oxide that has attracted interest for photovoltaic and optoelectronic applications, including third-generation photovoltaic devices. However, the production of ceramic targets with suitable density and microstructure for sputtering deposition remains a technological challenge. This study investigates a processing route for SrTiO3 ceramic targets and their application in thin-film heterostructures. SrTiO3 powders were synthesized by the Pechini method and densified by Spark Plasma Sintering (SPS), followed by deposition by RF Magnetron Sputtering of thin films. Structural and morphological analyses confirmed the formation of predominantly cubic SrTiO3 and the densified microstructure of the ceramic target. The optical band gap of the films, determined using the Tauc method for an indirect transition, was 3.42 eV for the as-deposited film and 3.35 eV after annealing. The resulting FTO/SrTiO3/CdTe/CdCl2/Au heterostructure exhibited a measurable photoelectric response, with localized photovoltage reaching approximately 400 mV, and photovoltaic parameters of Jsc = 4.32 μA/cm2, Voc = 9.75 mV, and FF = 21.4%. These findings demonstrate the feasibility of the proposed processing route for producing SrTiO3 thin films and their integration into photoactive heterostructures.