Tin-doping effect on improving stability of perovskite quantum dots

Perovskite quantum dots (PQDs) have a tunable emission wavelength by halide anions, as well as excellent blue light absorption, a very narrow full width at half maximum (FWHM), high color purity, and a wide color gamut, making them suitable for replacing traditional phosphors as backlight sources for white light emitting diodes (WLEDs). However, their practical application is limited by surface defects, poor stability, and the presence of heavy metals "lead (Pb)". This study prepared using the thermal injection method to reduce the Pb content through partial replacement with tin (Sn), Additionally, (3-Aminopropyl)triethoxysilane (APTES) was used to coating the perovskite quantum dots with SiO2,to enhance their stability. It was observed that the relative QY was extremely high, reaching up to 198%, with a Sn0.2-A (compared to 59% in literature). When adjusting different Pb-Sn ratios. After a period of time, the emission wavelength shifts by approximately 3 nm for Sn0.2-A and 1 nm for Sn0.5-A. Notably, the luminescence efficiency increases 1.7 times after two months. Both Sn0-A and Sn0.2-A maintain stable full-width at halfmaximum and improve efficiency (up to 1.4 times) after two months. Continuous irradiation for 60 minutes further enhances the efficiency of Sn0.2-A by 1.5 times. Therefore, tin-doped, silica-coated perovskite quantum dots effectively improve relative quantum efficiency and stability, reduce lead content, and present a more sustainable option for future market applications.