Incorporation of Cesium ions in FAPbBr3 quantum dots: Spectroscopic characterization for light-emitting application

• FA 1-x Cs x PbBr 3 PQDs were fabricated via the ligand-assisted reprecipitation processes. • FA/Cs based PQDs reported for the first time. • FA 1-x Cs x PbBr 3 PQDs have high color purity of > 88%. • Photoluminescence quantum yield (PLQY) of 85% for FA/Cs PQDs. • Exhibited good environmental stability in the ambient conditions. • The color gamut was 118% of the NTSC. Hybrid perovskite quantum dots (PQDs) are the good light harvesters due to their outstanding optical and electrical properties, which, aroused great interest of scientists in perovskite materials now a day. But FAPbBr 3 PQDs still suffering due to lower stability, complicated synthesis process and lower color gamut of devices. FA 1-x Cs x PbBr 3 PQDs were fabricated via the rapid ligand-assisted reprecipitation processes thru the variation in the concentrations of cesium (Cs + ) ions from 0 to 100 mol%. To overcome the stability issues, Cs + was incorporated into FAPbBr 3 PQDs that demonstrated distinctive PL emission peak shifting towards the blue region. FA 1-x Cs x PbBr 3 PQDs doped with 80 mol% of Cs + ions showed a high color purity of 88% as well as a photoluminescence quantum yield (PLQY) of 85%. Moreover, FA 1-x Cs x PbBr 3 PQDs doped with 80 mol% of Cs + ions exhibited good environmental stability in the ambient conditions. The color gamut of the synthesized white light-emitting devices fabricated with FA 1-x Cs x PbBr 3 PQDs at cesium concentrations of 80 mol% was 118% of the NTSC. The present research indicated that the incorporation of cesium ions in FAPbBr 3 PQDs was an effective method to prepare PQDs with a high PLQY, color gamut, narrow bandwidth emission, good environmental stability.