Synthesis, characterizations, and EMI shielding study of copper indium selenide (CuInSe2) nanoparticles

Synthesis of copper indium selenide nanoparticles (CISe NPs) was performed using hot-injection method using organometallic selenium-precursors. The large-scale synthesis is successfully demonstrated with consistent phase purity at applied reaction temperature between 200 and 250°C by practice of two different Se-precursors such as selenadiazole (SDZ) and diphenyl diselenide (DPDS), and capping agents e.g. oleic acid (OA) and oleyl amine (OLA). The prepared CISe NPs were characterized by UV–visible spectroscopy, XRD measurements, FESEM/EDX, HR-TEM, AFM, XPS and thermal conductivity to confirm the band-gap, crystalline phases, surface morphology, shape, size, elemental composition, surface topology, with oxidation states and thermal properties, respectively. The so-generated CISe with band-gap between 2.25 and 2.36 eV and mixed particle size of about 10–30 nm with hexagonal and cubic morphology were embedded in polyvinyl alcohol (PVA) to cast ∼0.6 mm thick films that showed excellent electromagnetic interference (EMI) blocking behaviour upon doping with nano-silver (Ag NPs). The EMI shielding effectiveness of about 55.3 and 50.8 dB in X-band and Ku-band respectively was achieved for CISe/Ag/PVA nanocomposite.