Enhancement of optical and magnetic properties of Fe‐doped ZnO nanorods synthesized via hydrothermal method for photosensor applications

ABSTRACT The Fe‐doped ZnO nanorods with varying Fe concentrations (0, 1, 3, and 5 wt.%) were successfully synthesized via a hydrothermal method. The structural, morphological, compositional, optical, magnetic, and photosensing properties of the fabricated samples were thoroughly examined using x‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy‐dispersive x‐ray spectroscopy (EDX), UV–vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL) analysis, vibrating sample magnetometry (VSM), and photoresponse measurements. XRD analysis confirmed a hexagonal wurtzite structure (space group P6mc) for all samples, with an increase in crystallite size from 45 (pure ZnO) to 55 nm (1 wt.% Fe‐doped ZnO). FESEM images revealed well‐defined nanorod morphology with uniform dispersion, and EDX verified the effective incorporation of Fe into the ZnO lattice. DRS measurements indicated bandgap energies of 3.187 (pure), 3.175 (1% Fe), 3.195 (3% Fe), and 3.180 eV (5% Fe). PL spectra suggested an enhanced electron–hole recombination related to oxygen defects in the 1% Fe‐doped sample. VSM studies confirmed room‐temperature ferromagnetic (RTFM) behavior in Fe‐doped ZnO. For photosensing performance, the 1% Fe‐doped ZnO nanorods exhibited optimal characteristics: responsivity (R) of 15.3 × 10 − 2 A/W, detectivity (D) of 1.5 × 10 9 Jones, and external quantum efficiency (EQE) of 49%. These findings demonstrate that the1 wt.% Fe‐doped ZnO nanorods are a promising candidate for efficient, low‐cost, and high‐speed photodetector applications.