Photoluminescence Characterization of CuInS2 Quantum Dots Incorporated in Hybrid Structures for Light Emission Devices

Abstract

In this work, hybrid multilayer structures containing CuInS₂ quantum dots coated with ZnMgO shells and incorporated in conductive polymeric matrices (PEDOT:PSS and TFB) were prepared and characterized to develop eco-friendly toxic-free light emitting devices. Results showed that addition of formamidinium acetate (FAAc) lead to enhance the microstructure by reducing the agglomerations and surface roughness to support the homogeneity and connection of the grains. The existence of all organic and inorganic constituents was confirmed with dominant carbon bonds distinguishing the polymeric layers. The photoluminescence (PL) spectroscopy revealed a reasonable enhancement in the intensity of the emitted light as well as a slight redshift due to treatment with FAAc. The electrical characteristics showed the behavior of negative differential resistance at high voltages due to heating and charge collection effects at the interfaces. A maximum value of external quantum efficiency (EQE) of 10% was achieved at applied voltage of 6.5 V as the radiative recombination dominates. These results reveal that the FAAc-treated hybrid structures show promising optoelectronic characteristics for low-cost light emitting devices with high color purity and stable performance at high voltages.