Air-Stable and Environmentally Friendly Full Color-Emitting ZnSeTe/ZnSe/ZnS Quantum Dots for Display Applications
Seongwoo Cho, Sung Nam Lim, Hye-Seon Kim, Shin Ae Song, Ki-Young Kim, Kuk Young Cho, Ju Young Woo
Abstract
We have developed a nontoxic method of synthesizing blue-emitting ZnSeTe/ZnSe/ZnS quantum dots (QDs), which can be employed to realize QD-based electroluminescent displays. By introducing excessive metal halides without highly toxic hydrofluoric acid, we achieved a very high photoluminescence quantum yield reaching 94%. Furthermore, for the first time, air-stable ZnSeTe/ZnSe/ZnS QDs were demonstrated by employing simple surface ligand exchange performed both in solution and solid states. Various spectroscopic studies revealed that initial carboxylate ligands could be very effectively replaced by our simple ligand exchange at room temperature. In addition, we significantly broadened the spectral range of QDs by increasing the Te ratio of the core; therefore, green- and red-emitting ZnSeTe/ZnSe/ZnS QDs were demonstrated. The air-stable Zn-based QDs with full color emission developed in our study can be used as superior emitters in displays.