Fabrication And Luminescence Performance Of CuInS Based White Quantum Dot Light Emitting Diodes

The high quality colloidal QDs based WLEDs have been achieved, havingcurrent efficiency of 120 lm/W, the CRI of over 99, and the emission tunable from cold to warm within these 20 years in the field of solid state lighting. Seemingly bright prospects are the illusion. These high quality QDs containing toxic heavy metals such as cadmium and lead would bring environmental and health problems.Therefore, people focus gradually on the low toxicity, heavy metal-free semiconductor QDs in fabrication of QD-LEDs. The emissions of ?-?-? based CIS QDs from near infrared to visible light can be acquired through the composition and size regulations. Due to their luminescence efficiency reaching as high as 70-90%,CIS QDs are suitable for the lighting and display. However, these environmentally friendly white QD-LEDs show some far poorer performance than the Cd or Pb based QD-LEDs. Therefore, optimizing the luminescence properties and the preparation of CIS based QD-LEDs are particularly urgent. First this thesis reports the preparation of the CIS based QDs and their luminescence properties as well as the geometry regulations of QDs by mixing green CuInS₂/ZnS QDs with red CuInS₂/ZnS and CdSe/ZnS QDs and changing the order of green and red QD emission layers to get high-performance QD-LEDs. Second, the Cu:ZnInS@ZnS:Al core-shell QDs with an aluminum doped ZnS shell were synthesized and the improved thermal stability is demonstrated. Furthermore white QD-LEDs with a thick shell-coated CdSe/CdS/ZnS QDs are fabricated. The related research ideas and experimental results are discussed in this thesis.