Multicomponent Photoluminescence Emission Tuning in CoS/Se core-shell Quantum Dot Thin Films for Light Emitting Applications

Abstract

In this work, novel sulfide-based chalcogenide core-shell quantum confined structures Cobalt Sulfide/Selenide (CoS/Se) will be synthesized by a facile wet chemical route and will be deposited onto conducting oxide-coated glass substrates as thin films via spin coating technique. Depending on temperature and reaction time, the hot injection method will synthesize the core-shell structure. The QD dispersions will then be deposited onto conducting oxide-coated glass substrates (FTO) under variant deposition conditions such as varying the number of deposition cycles. RAMAN spectroscopy is used to study the vibrational modes, identify structures, and detect oxygen-related defects. The Raman analysis clearly shows the dominant Raman modes of CoSe. The PL spectra show the emission of CoS, CoSe, and CoS/CoSe in the visible region. The band samples' band gaps, particle sizes, and Urbach energies were timed by analyzing absorbance spectroscopy (UV- VIS Spectroscopy) measurements. The ellipsometry measurements were done to study the refractive index, extinction coefficient, and transmittance of different layered spin-coated thin films of CoS/CoSe core/shell QDs. These FTOs don’t behave as a polarizer. The synthesized CoS/CoSe Core/ shell QDs can be the potential candidate for optoelectronics devices.