Optoelectronic and thermoelectric applications of Pr and Nb Doped SrTiO3 Nanostructures

Abstract

he increasing global demand for sustainable energy has driven extensive research into oxide-based multifunctional materials capable of efficient energy conversion and optical functionality. Perovskite oxides such as strontium titanate (SrTiO:) have emerged as promising candidates due to their exceptional thermal stability, environmental compatibility, and tunable electronic structure. This research work focuses on the optoelectronic and thermoelectric applications of Praseodymium (Pr) and Niobium (Nb) doped SrTiOs nanostructures, with the objective of achieving simultaneous enhancement of optical transparency, carrier mobility, and thermoelectric performance through controlled defect and dopant engineering. Pr doping at the A-site induces structural distortion and bandgap reduction, enablingstrong visible and infrared absorption as well as tunable photoluminescence emission. Nb substitution at the B-site significantly enhances carrier concentration and electrical conductivity, improving the thermoelectric power factor. Advanced synthesis techniques such as graphite burial sintering and RF magnetron sputtering were employed to manipulate oxygen vacancy concentration and lattice strain, leading to record power factors approaching 1.85 mW/mK? and high carrier mobility. The integration of experimental optimization and defect modulation provides a scalable route to fine-tune the electronic band structure and transport behavior. Furthermore, a custom-designed magneto-thermoelectric measurement setup was developed to investigate the influence of magnetic fields on thermoelectric voltage generation, offering new insights into carrier-magnetic field interactions. Overall, this study demonstrates how strategic doping, oxygen vacancy engineering, and thin-film processing can transform SrTiO; into a high performance multifunctional oxide, paving the way for its application in transparent electronics, photonic energy devices, and next-generation thermoclectric technologies.