High efficiency green and red emitting CdSeTe quantum dots: Synthesis and PLQY improvement for optical applications

Obtaining stable QDs with different emission colors and high PLQY values for optoelectronic applications is important. There are currently applied treatment methods to increase the PLQY value and stabilization of QDs. On the other hand, variations in the surface-to-volume ratio associated with changes in QD size indicate that the treatment methods applied must be optimized according to the specific size of the QDs. This study focuses on the optimization of the synthesis and treatment processes of green and red emission CdSeTe QDs with high PLQY for use in optoelectronic devices. Initially, the synthesis processes for green and red emission QDs were optimized according to precursor molar amounts, synthesis time and synthesis temperature. Then, chloride treatment, CdS and ZnS shell coating methods were optimized and applied separately to increase the PLQY values of these QDs. The results showed that the PLQY value increased up to 95.23 % with 30 % CdCl2 treatment by mass for green emitting CdSeTe QDs and up to 96.31 % with 40 % CdCl2 chloride treatment by mass for red emitting QDs. The study includes a comprehensive comparison of emission, absorption, XRD, elemental analysis, CV, PL lifetime, HR-TEM analysis and stabilization analysis for the synthesized CdSeTe QD types.