Unveiling the impact of defects on Fe³⁺-doped Tin tungstate materials for next generation optoelectronic applications

This study explores the theoretical calculations on the optical, and electronic properties of pure and Fe³⁺ doped SnWO₄, focusing on defect engineering and its impact on optoelectronic applications. SnWO₄, exhibiting two phases like α-SnWO₄ and β-SnWO₄, is explored due to its potential in semiconductor, photocatalytic, and photovoltaic applications. Defects, such as vacancies (V_Sn, V_W, V_O), were introduced in both pristine and Fe³⁺ doped SnWO₄ systems, and their formation energies and activation energies were computed to understand their thermodynamic stability and influence on electronic properties. The results indicate that Fe³⁺ doping alters the defect levels, reducing the formation energies, particularly for oxygen vacancies, which enhances the material's electronic and optical performance. Additionally, density of states (DOS) and energy band diagrams show the creation of new energy levels within the band gap due to Fe³⁺ doping and defect formation, which contribute to improved charge transport and light absorption. SCAPS-1D simulations were performed to model the device performance, revealing that Fe³⁺ doping increases both open circuit voltage (V_OC) was found to be 1.54 V and short circuit current density (J_SC) was 20.72 mA/cm², are maximum for Fe³⁺ doped SnWO₄, resulting in higher efficiency compared to undoped SnWO₄. The findings highlight the crucial role of defect engineering and Fe³⁺ doping in enhancing the properties of SnWO₄ for next-generation optoelectronic devices, such as solar cells and photodetectors. This work provides valuable insights into optimizing SnWO₄ for advanced applications through defect substitutions and doping strategies.