Stability improvement of photoluminescent QLEDs based on Mn-doped all-inorganic metal halide perovskite quantum dots with silica shell

Highlights: • We report the synthesis of Mn-doped CsPbCl₃ QDs and silica-coated Mn:CsPbCl₃ QDs. • Light-emitting diodes based on silica-coated Mn:CsPbCl₃ QDs are fabricated. • The as fabricated devices exhibit improved performance stabilities. -- Abstract: Perovskite quantum dots (PQDs) suffer from the long-time stability owing to their strong ionic structure. Wrapping them with silica or doping them with ions have been used to improve their structural stabilities. Here, transitional metal doping and surface engineering are employed to synthesize silica-coated Mn:CsPbCl₃ QDs for the fabrication of photoluminescent QD-based light-emitting diodes (QLEDs). The as synthesized QDs have dual emission, one is the intrinsic emission of the perovskite host, and the other is the Mn-related emission. The as synthesized Mn-doped CsPbCl₃ exhibit improved stability of luminous spectra compared to those of the pure ones. We also integrate the silica-coated Mn:CsPbCl₃ QDs as color converters with a purple chip. The luminous spectra of the photoluminescent QD-based light-emitting diodes (QLEDs) can be adjusted by controlling the QD concentration. Twenty-day observation and measurement show that devices based on the silica-coated Mn:CsPbCl₃ exhibit enhanced performance stabilities, including a maximum CRI fluctuation of 2.3, a maximum CCT fluctuation of 7 K and a maximum LER fluctuation of 5.2 lm/W_opt. These results indicate that manganese doping and silica shell are helpful for the stability improvement of perovskite QDs, and the potential applications of silica-coated Mn:CsPbCl₃ QDs in lighting fields.