Effect of hydrazine hydrate on the luminescence properties of MPA capped CdTe nanocrystals in hot injection method

In this research MPA capped CdTe nanocrystals with sizes around 2.7-3.5 nm were grown in aqueous solution. The process was performed through the reaction of NaHTe with MPA and CdCl2 solution in high temperature. The synthesis was carried out in two different states of standard and modified forms. In the modified synthesis, the hydrazine hydrate material was added to the MPA plus CdCl2 solution before injection. The evolution of the nanocrystals size and PL quantum yield was monitored during the heating time for the growth. The results demonstrated that for the standard synthesis the growth rate was slow. The CdTe nanocrystals with high PL quantum yields were achieved in more than 10 h of heating. In contrast for the modified synthesis the growth rate was considerably higher. In this state a band edge emission with PL quantum yield of about 26% was achieved for the MPA capped CdTe nanocrystals in just 2 h of the heating process.