CONJUGATED POLYMER-PEROVSKITE NANOCOMPOSITES FOR OPTOELECTRONICS

Abstract

Metal halide perovskite semiconductors are a new material class that has shown great promise for a range of optoelectronic device applications. Due to their emission wavelength tunability throughout the visible spectrum and EQE of over 20%, they have shown to be very promising materials for light-emitting diodes. Nevertheless, further work must be done to enhance their properties for practical uses. Several approaches, including as ligand modification and polymer mixing, are developed to address these problems and demonstrate improvements in the characteristics and performance of devices. Thus, conjugated polymer perovskite CsPbX3 (x=halide, their combinations) nanocrystal (NCs) composites is the main focus of our work. The synthesis of perovskite NCs was carried out at room temperature utilizing a type of ligand assisted recprecipitation method called supersaturation recrystallization. Then,a solution mix approach was then used to perpare the composites of conjugated polymer with perovskite nanocrystals. Initially, we look into how ligands affect the characteristics of all- inorganic halide perovskite CsPbBr3 that is produced by supersaturated recrystalizaion(SR) methods at room temperature. Here, the structural and optical characteristics of CsPbBr3 produced using ligand systems (oleic acid/oleylamine versus olive oil/oleylamine) were investigated. In this case, the optical band gap value is 2.3 eν and cube-shaped nanocrystal with crystallite size of 40-42 nm achieved during the utilization of two ligand species combinations. In contrast, a longer decay life time ,i.e., 3.228 ns was seen in the ligand combination of olive oil and oleylamine as compared to oleic acid and oleylamine which is 1.167 ns. Secondly, separate preparations were made for the conjugated polymer and the CsPbBr3 solution. Subsequently, two precursor solutions were combined utilizing a solution blend approach, which included varying sample ratios and was characterized by a number of techniques. Nanostructure and characteristics in the conjugated polymer-perovskite nanocomposite were investigated. Using Flory Huggins' theory, the miscibility of polymers with solvents, ligands, and perovskites was predicted. As the amount of perovskite CsPbBr3NCs in the MDMO-PPV polymer matrix increases, it is evident in the crystallite size shift, which ranges ~33 to 52 nm. According to scanning electron microscope images display that CsPbBr3QDs can be highly aggregated at MDMO PPV:CsPbBr3= 50:50 composition. Additionally, there is an improvement in emission PL, with more than or equivalent to 30 Wt% of CsPbBr3NCs observed. Furthermore, it was xiv observed that the conjugated polymer and perovskite nanocrystal overlapped in terms of both PL emission donor CsPbBr3 and acceptor MDMO-PPV absorption, indicating a potential energy transfer between the two materials.Here, the charge transfer-resistance is decreased in the 50:50 of MDMO-PPV/CsPbBr3 composite, showing that the composite has better charge transport properties than the pristine MDMO-PPV. Finally, simple synthesized of mixed halide perovskitewas condcuted by SR methods at room tempertaure.Then, mixed hadlide perovskite Ncs doped into conjugated polymer was carried out. The composite of CsPb(Br1-xClx)3 doped into MDMO-PPV shows an improvement in crystallite size as the concentration of mixed halide perovskite increases with chlorine content rise compared to pristine polymer. Simialrily, the PL emission shows enhancement as content of chlorine rise in the composites. In conclusion, our research indicates that the pure perovskite CsPbBr3 generated utilizing the recommended lignad combination and the polymer-perovskite nanocomposite exhibits improved properties. Therefore, the finding was suggested that in the future this technique holds promising for use electrochemical and optoelectronic applications.