Enhancement of luminous properties and stability of CH3NH3PbBr3 perovskite quantum dots using a low-cost, environmentally friendly and multisite passivation strategy

CH 3 NH 3 PbBr 3 perovskite quantum dots (PeQDs) have demonstrated excellent performance and are promising for optoelectronic applications . However, poor stability caused by surface defects severely limits their further development. In this work, cheap, green Tartaric acid (Ta) was introduced as a multisite passivator for the synthesis of CH 3 NH 3 PbBr 3 PeQDs by ligand-assisted reprecipitation at room temperature , and the effect of Ta on the luminous properties and stability of CH 3 NH 3 PbBr 3 PeQDs was investigated. The hydroxyl group of Ta can anchor Br − of PbBr 6 4− octahedra , reducing the Br vacancy by reducing surface Br − loss, and the carboxyl group can form a coordination bond with Pb 2+ , all contributing to reducing surface defects , inhibit heavy metal leakage, reduce toxicity and improve luminous properties and stability. The results showed that the FWHM (full width at half maxima) of the Ta-modified PeQDs was 19 nm, PLQY reached 88.24 % and showed bright fluorescence for 100 days at room temperature. Ta-modified PeQDs-based white LED (WLED) emitted cold white light, with ultrahigh luminous efficiency of 121.57 lm/W, color gamut of 127 % of the National Television System Committee (NTSC) standard and high operate stability. Our work provides new ideas for low-cost preparation of perovskite devices with high optoelectronic performance.