Ultrahigh stable KCsPbBr3 quantum dots in lithium disilicate glass powders with super wide excitation band and narrow Stokes shift

Inorganic perovskite quantum dots (PQDs) have great potential in display, lighting and other fields because of their high optical properties, narrow fluorescence emission half-peak width and convenient synthesis. However, the large Stokes shift (more than 155 nm) of KCsPbBr 3 PQDs results in more energy loss, and the maximum excitation peak is normally located at near-ultraviolet (NUV) region (∼365 nm), greatly limiting its application in lighting and displays based on blue light emitting diodes (LEDs). Herein, KCsPbBr 3 PQDs in lithium disilicate glass powders with a super broad excitation band in the range of 330–450 nm and narrow Stokes shift of ∼67 nm has been developed. Lithium disilicate glass with excellent mechanical properties are introduced as rigid armor to keep CsPbBr 3 PQDs from thermal and moisture attack, even maintaining the average particle size of ∼2.4 nm after high temperature calcination (600 °C). Interestingly, photoluminescence excitation spectrum of KCsPbBr 3 PQDs glass calcined at 600 °C presents which is entirely consistent with the emission wavelength of NUV and blue LEDs. In addition, the photoluminescence intensity of KCsPbBr 3 PQDs in lithium disilicate glass powders increases firstly and then decline sharply after calcination 600 °C, which exhibits with a narrow full width at half peak (FWHM) of ∼20 nm. The KCsPbBr 3 PQDs glass exhibits ultrahigh stable properties and maintains the photoluminescence emission intensity even soaked in deionized water for more than 85 days, indicating a great potential in fields such as green or white light lighting and fingerprint recognition.