Impact of Y₂O₃ Nanosheets on the Microstructural Characteristics of Alq₃ Prepared via the Co-precipitation Route for Enhancement of Photodiode Performance

In the present study, tris-(8-hydroxyquinoline) aluminum (Alq₃) and tris-(8-hydroxyquinoline) aluminum/yttrium oxide Alq₃/Y₂O₃ were synthesized by a facile chemical route. The crystal structure, surface morphological nature, and particle size were identified by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) micrographs. Ag/Alq₃/p-Si/Al and Ag/Alq₃:Y₂O₃/p-Si/Al diodes were fabricated by the thermal evaporation technique and the electrical characteristics were evaluated from the I–V plots in dark and under illumination intensity. Thermionic emission theory, Cheung–Cheung, and Nord model have been applied to define the main electronic parameters like series resistance (R_s), barrier height (ϕ_b), and ideality factor (n). The hybrid Ag/Alq₃:Y₂O₃/p-Si/Al diode revealed a nonideal behavior with high shunt resistance R_sh and good photocurrent sensitivity. The C/G–V analysis indicated that both C and G are strongly affected by the presence of trapped charge carriers at the interface states. The obtained results indicated that R_s was decreased whereas the carrier concentration (N_a) was increased by loading Y₂O₃ nanosheets.