Akademik Veri Yönetim Sistemi
Journal of Alloys and Compounds, cilt.1040, 2025 (SCI-Expanded)
In this study, zinc oxide (ZnO) thin films co-doped with 15 % iron (Fe) and 1 % boron (B) (Zn₀.₈₄Fe₀.₁₅B₀.₀₁O) were successfully synthesized on glass and silicon (Si) substrates using sol–gel-based dip-coating and spray-coating techniques. The optoelectronic, thermoelectric, electrical, and optical transmittance properties of the films were systematically investigated as a function of film thickness (4, 6, 8, and 10 layers). Structural analysis revealed that the produced thin film consisted of an approximately 98 % amorphous matrix with about 2 % nanocrystalline regions exhibiting a wurtzite ZnO structure, with particle sizes ranging from 11 to 350 nm. Photoluminescence (PL) spectroscopy exhibited band-edge emission at 3.26 eV, along with defect-related peaks at 2.42 eV and 1.80 eV. The pronounced intensity of the 1.80 eV peak compared to the UV emission indicates a high density of deep-level defects. Electrical measurements demonstrated a thickness-dependent transition from diode-like to quasi-metallic behavior. This was evidenced by increasing ideality factors from 3.95 to 4.62, decreasing contact barrier heights from 0.608 eV to 0.511 eV, and reduced series resistance values from 23.6 kΩ to 21.0 kΩ. Although the overall optoelectronic performance was limited, the 6-layer sample exhibited the highest solar cell efficiency. In contrast, the 4-layer film displayed promising thermoelectric characteristics, including a Seebeck coefficient of −5600 µV/K, a power factor of 100 µW/m·K², and a figure of merit (ZT) of 0.006 at 500 K. Additionally, the lowest thermal conductivity (2.3 W/m·K) was observed in the thickest sample (10-layer), likely due to enhanced structural disorder and phonon scattering. These findings underscore the potential of amorphous 15 %Fe–%1B co-doped ZnO thin films as cost-effective materials for thermoelectric energy harvesting, despite the limitations posed by deep-level defects in photovoltaic and photodetector applications.