In this work study, we focused on the study of the structural and optical properties of the chemical precipitation derived special shape (budding twigs of flower type) ZnO nanostructures for optoelectronic and photodetection applications. The details of the structural and optical properties of the budding twigs of Jasminum flower, like ZnO nanocrystals, have been studied and discussed from the XRD, HRTEM, UV-Vis &and photoluminescence Spectrum. The grown ZnO nanocrystals has beenwere coated onin 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-dependantlight-dependent (λ~366nm) 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 beenwere examined. The diode has a well-defined rectifying behaviour 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 2.095x1017 cm-3 respectively. The change in heterojunction capacitance, barrier height, depletion width and other parameters of the heterojunction photodiode under UV illumination has beenwere discussed. The qualities of the device demonstrate that it tends to be utilized for UV photodetection applications in nano-optoelectronic and photonic devices.