One-dimensional semiconducting Hf_xZn_1−xO nanorods and their photoswitching characteristics

Hafnia zinc oxide (Hf_xZn_1−xO) nanorod-like structures were processed for photoswitching applications through a facile chemical strategy. Their crystalline structure and phase purity were examined by X-ray diffraction and Raman analysis. The evolution of Hf_xZn_1−xO in rod-like configuration was inferred through scanning and transmission electron microscopy. The band gap values of Hf_xZn_1−xO were estimated using Tauc's plot to be around 2.89–3.11 eV. The association of multiple defects within the hafnia based nanorods was further substantiated through luminescence results via sub-band signals in near visible region. Nyquist and bode plots of Hf_xZn_1−xO nanorods were extracted from the electrochemical impedance spectroscopic results to evaluate the role of grain boundaries on their conductivity values. The electrical properties of Hf_xZn_1−xO nanorods including their carrier density were estimated by capacitance vs. voltage (1/C² vs. V) measurements. The photoswitching potential of n-Hf_xZn_1−xO was investigated by spin casting the nanostructures on p-Si and investigating the diode's charge transfer characteristics. The Hf composition in the respective diode architecture was found to influence their corresponding photocurrent values.