Physical properties of CdO nanoparticles synthesized by green chemistry via Hibiscus Sabdariffa flower extract

Abstract The first time synthesis of CdO nano-crystals by green chemistry process based on Hibiscus Sabdariffa flower extract and their main physical properties are reported. While it is shown that the natural extract acts as an effective chelating agent in facilitating the formation of the CdO nanoparticles, the structural analysis by X-rays diffraction analysis shows that the nano-crystals exhibit a pure single phase Monteponite. Their photoluminescence display a relatively an intense and narrow emission peak at 551 nm. Their direct and indirect bandgaps were found to be 2.7 and 2.1 eV. The investigation of their surface properties showed the existence of a double coordination: presence of CdO and CdO2 type bonds. The current–voltage characteristic of the CdO nanoparticles film/c-Si heterojunction solar cell under dark and illumination conditions showed that such a heterojunction has acceptable rectification characteristics with a forward current saturating at ∼1 V.