Synthesis of Symmetrical Silane Containing P═O Bonds and Their Passivation of Perovskites

Perovskite quantum dots (QDs) exhibit unique advantages, including a wide color gamut, narrow full width at half-maximum, cost-effectiveness, and high-efficiency luminescence, positioning them as a significant focus in contemporary optoelectronic research. Nevertheless, the synthesis of QDs often introduces crystal defects, while conventional in situ ligands can detrimentally affect the optoelectronic properties of perovskites. To overcome these challenges, we synthesized a symmetrical silane-based passivating agent containing phosphorus–oxygen double bonds. This agent enabled the in situ passivation of perovskites, significantly improving their optical performance and stability. Results showed that postpassivation QDs demonstrated bright green photoluminescence (PL) at 525 nm, with a 28% enhancement in PL intensity, a 16% increase in photoluminescence quantum yield, and an average lifetime (τave) extended by 191.2 ns. Furthermore, the thermal stability at 80 °C improved by 3.75-fold, and the stability under 84% relative humidity conditions increased by 21%. 1,3-bis(3-diethoxyphosphorylpropyl)-1,1,3,3-tetramethyldisiloxane (SPE)-passivated perovskites are viable for practical applications.