Effect of molar concentration on optoelectronic properties of α-Fe2O3 nanoparticles for n-α-Fe2O3/p-Si junction diode application

Abstract

In present work, we have synthesized rhombohedral structured α-Fe₂O₃nanoparticles (NPs) for various molar concentrations of 0.25, 0.5, 0.75, and 1 M using a simple co-precipitate method. X-ray diffraction analysis confirmed the formation of single-phase rhombohedral structured α-Fe₂O₃ NPs. The Raman characteristic peaks exhibited a pure hematite phase, free from iron oxide and iron hydroxide impurities. FESEM showed a randomly oriented submicron-sized and irregular granular-shaped structure of the synthesized α-Fe₂O₃ NPs. The fundamental stretching and bending vibrations of chemical bonds and the existence of Fe‒O functional groups were captured from FTIR spectra. UV–Vis absorption spectral analysis showed a strong optical absorption peak in the range of 350–550 nm. Moreover, A minimum optical band gap of 1.7 eV as observed for 1 M of α-Fe₂O₃ NPs. Based on the beat outcome, we have developed n-α-Fe₂O₃/p-Si junction diode for 1 M of α-Fe₂O₃ NPs and measured forward and reverse current values for dark and light environments. Remarkably, the diode exhibited a lower ideality factor of 3.4 under light exposure. Furthermore, the n-α-Fe₂O₃/p-Si diode demonstrated a quantum efficiency of 38 % and a detectivity of 1.98 × 10¹⁰ Jones, indicating its potential for future optoelectronic applications. These results strongly support the suitability of the fabricated n-α-Fe₂O₃/p-Si diode for advanced optoelectronic technologies.