Defect-Driven Optical Modulation in Rare-Earth-Modified Zn₂SnO₄ Spinels for Advanced Optoelectronic Applications

Area of Science:

• Materials Science
• Solid-State Chemistry
• Optoelectronics

Background:

• Spinel Zn2SnO4 is a semiconductor with potential applications.
• Aliovalent substitution can modulate material properties.
• Understanding structure-property relationships is crucial for material design.

Purpose of the Study:

• To synthesize and characterize La- and Ce-doped Zn2SnO4.
• To investigate the effects of aliovalent substitution on structural, optical, and photoluminescence properties.
• To establish correlations between structure, defects, and optical behavior.

Main Methods:

• Solid-state synthesis route.
• Characterization using X-ray diffraction (XRD), FTIR, Raman, UV-Vis spectroscopy, photoluminescence, SEM-EDS, and XPS.
• Analysis of structural, optical, and luminescence properties.

Main Results:

• Cubic spinel structure confirmed with minor SnO2 phase.
• Rare-earth incorporation led to lattice expansion, microstrain, and reduced crystallite size.
• Band gap narrowed, extending visible-light activity (3.57 eV to 3.12 eV).
• Dopant-selective color tuning observed: orange emission for La-doped, green for Ce-doped.
• Enhanced oxygen-vacancy-related defects and presence of various metal ion states.

Conclusions:

• Aliovalent substitution effectively modulates structural, optical, and photoluminescence properties of Zn2SnO4.
• Rare-earth doping induces specific defects and band gap changes.
• Modified Zn2SnO4 shows promise for visible-light optoelectronics, luminescence, and optical sensing.