Siloxane-Modified ZnMgO Nanoparticles with Enhanced Colloidal Stability and Improved Quantum Dot Light-Emitting Diode Stability

ZnMgO nanoparticles are widely used as the electron transport layer for quantum dot light-emitting diode (QLED) applications but suffer serious stability issues. In this work, we developed siloxane-modified ZnMgO nanoparticles to address stability issues. At room temperature, colloidal ZnMgO nanoparticles usually undergo aggregation-induced turbidity within 3 days. With the addition of a tetramethyl orthosilicate (TMOS) precursor into the preformed ZnMgO nanoparticles, the siloxane-modified ZnMgO nanoparticles show enhanced colloidal stability, which is stable for more than 40 days. We further compared the device stabilities of unmodified and siloxane-modified ZnMgO nanoparticles. The results show that siloxane-modified ZnMgO-based devices show enhanced operation and storage stability. In particular, the operational lifetime was improved by 59.3%, and the luminance at 5 V can be kept at about 75% after 80 days of storage. In all, this work provides an effective strategy to address the stability issues of ZnMgO nanoparticle-based optoelectronics.