SYNTHESIS AND CHARACTERIZATION OF HIGHLY FLUORESCENT CsPbBr3 & CsPbBr2I PEROVSKITE QUANTUM DOTS FOR OPTOELECTRONIC APPLICATIONS

Abstract

Highly fluorescent Cesium Lead-based inorganic metal halide semiconductor perovskites have gained immense popularity in the past decade due to the economic and straightforward techniques involved in fabricating these materials and their excellent electrical and optoelectronic properties. These desirable properties of Cesium Lead halide perovskites have piqued the interest of many researchers from different fields of science and technology and encouraged them to study as well as improve the optoelectronic properties of these materials for use in other electronic as well as optoelectronic applications such as highly efficient photovoltaic cells, photodetectors, light-emitting transistors, transistors, and perovskite Light Emitting Diodes (PeLEDs). Perovskite-based devices have shown promising optoelectronic properties and have an extremely high potential for commercialization. Cesium lead halide perovskite quantum dots are well known for their fluorescence in the visible region with extremely high quantum efficiencies (as high as 90%), thus making them highly suitable for commercialization as materials for the fabrication of efficient light-emitting diodes. Many researchers have successfully fabricated LEDs based on these materials and reported very high efficiencies, but these devices are plagued with poor stability, primarily due to moisture. Moreover, the electrodes for these devices are fabricated using very sophisticated technologies, thus increasing the cost of production. In the present study, perovskite quantum dots of CsPbBr3 and CsPbBr2I were synthesized via Ligand Assisted Reprecipitation (LARP) method at Room Temperature. LARP is an attractive, cost-effective, and relatively simple method for synthesizing highly monodisperse CsPbX3 perovskite quantum dots. This work focuses on the room temperature synthesis and characterization of the CsPbBr3 and CsPbBr2I perovskite quantum dots and measurements of their optoelectronic properties. Different characterization techniques have been employed in this project to understand better the structural, morphological, and crystalline properties and the various factors affecting the stability and optoelectronic properties of these prepared quantum dots. The main motive behind this project is to synthesize highly monodisperse and stable quantum dots via a cost-effective and straightforward method at room temperature, free from sophisticated processes and an inert atmosphere.