Recently, the development of opto-electronics that is integrated with ultra-broad spectral range has attracted tremendous attention. The fabricated devices should have high photoresponsivity, specific detectivity and fast switching. Herein, efforts have been applied to synthesis WS2-ZnO (WZO) heterostructure using high-yield microwave assisted synthesis and to fabricate large area WZO/Si heterojunction photodiode. The efforts have also been applied to find number of atomic layers in WS2 nanosheets using Raman spectroscopy and absorption spectroscopy. The WZO/Si photodiode exhibits current rectifying behaviour (with rectification ratio 155 at 1.5 V), self-powered photodetection, improved photoresponsivity and detectivity in broad in spectral range 390-1080 nm and higher electrical stability in dark and under illumination. Present findings advocate the huge development in facile fabrication of high-performance opto-electronics over previously reported devices.