Enhancing photoresponsivity of ultra violet photodetectors based on Fe doped ZnO/ZnO shell/core nanorods

In this work, the structural, electrical and optical properties of pure and Fe doped ZnO/ZnO shell/core nanorods samples with different Fe concentrations (0-9 at.%) were studied. The samples were prepared using a two-step method; hydrothermal followed by dip coating for encapsulation process. The X-ray diffraction (XRD) results showed the Fe doping improved the crystallinity of ZnO nanorods at an optimized value (4.5 at.%). The encapsulation increased nanorods diameter by magnitude ∼20-40 nm. The structural and optical properties evidenced the Fe ions substituted with valence state 3+ into Zn2+ sites. The I-V measurements showed that resistance was increased with increase in Fe-doping due to increase carrier concentration confirmed existence of Fe ions in valance state 3+. The photoresponsivity of UV photodetectors based Fe doped ZnO nanorods demonstrated an increase trend with Fe doping.