Low temperature synthesis of highly bright green emission CuInS2/ZnS quantum dots and its application in light-emitting diodes

In this study, an efficient green light-emitting CuInS 2 /ZnS core/shell quantum dots were synthesized using a low temperature (130 °C) hot injection methods combined with multi-layers ZnS coating strategy. S-OAm (S powder dissolved in oleylamine) was used as sulfur source instead of conventional dodecanethiol, which supplied high concentration of H 2 S at low temperature and led to explosive nucleation of CuInS 2 and hence high concentration small size of CIS cores. Meanwhile, this method could supply enough sulfur sources for the ZnS coating process , resulting in high quality ZnCuInS 2 alloyed interface and ZnS surface coating layers, which led to excellent lattice match between the CuInS 2 core and ZnS shells, and better surface passivation . As the consequence, a maximum photoluminescence quantum yields of ∼85% at peak wavelength of ∼530 nm has been achieved. Based on this, the light emitting diodes with a maximum luminance of 4450 cd m −2 , luminous efficiency of 3.52 cd A −1 and an external quantum efficiency of 1.44% has been obtained, which is the best result so far for the green emission light emitting diodes based on the CuInS 2 quantum dots.