Characterization of budding twigs of flower-type zinc oxide nanocrystals for the fabrication and study of nano-ZnO/p-Si heterojunction UV light photodiode

Abstract

In this work, we focused on the study of the structural and optical properties of chemical precipitation-derived special shape (budding twigs of flower-type) ZnO nanostructures for optoelectronic and photodetection applications. The structural and optical properties of the budding twigs of Jasminum flower-like ZnO nanocrystals have been studied and discussed in detail from the XRD, HRTEM, UV–Vis, and photoluminescence spectra. The grown ZnO nanocrystals have been coated on the p-Si substrate to fabricate nano-ZnO/p-Si heterojunction photodiode. The junction properties of the fabricated photodiode were examined by measuring ultraviolet (UV)-light-dependant (λ ~ 366 nm) and dark condition current (I)–voltage (V) as well as capacitance (C)–voltage (V) characteristics. The photodetection properties of the diode in the UV light region have been examined. The diode has well-defined rectifying behavior with a photoresponsivity and external photodetection efficiency of 0.065 and 21.5%, respectively. The observed barrier height and donor concentration under dark condition were ≈ 0.25 eV and 2 × 1017 cm−3, respectively. The change in heterojunction capacitance, barrier height, the depletion width, and other parameters of the heterojunction photodiode under UV illumination has been discussed. The qualities of the device demonstrate that it tends to be used for UV photodetection applications in nano-optoelectronic and photonic devices.