Preparation And Exploration Of Optical Functional Materials:CsPb₂Br₅ Quantum Dots Glasses And Agates

All-inorganic cesium lead halide?CsPbX₃,where X=Cl,Br,or I?perovskite quantum dots?QDs?is very attractive for lighting and display technology because of their tunable photoluminescence?PL?over a broad range of the visible spectrum?400-700 nm?with high PL quantum yields?QYs?of up to 90%and narrow full widths at half-maximum?fwhms?.colloid properties of CsPbX₃ QDs prepared by hot-inject approach still exist the problems of air and thermal instability.Therefore,we have incorporated all inorganic lead halides perovskite quantum dots into some stable glass matrix materials and then through a number of modern testing analysis to study its morphology,microstructure and its optical properties.In addition,we also explore the composition and optical properties of natural gemstones.The main contents are as follows:?1?Based on the previous experiment,CsPb₂Br₅ QDs glasses have been successfully fabricated under various temperatures of heat-treatment through a conventional melting-quenching technique.Moreover,photoluminescence?PL?spectra of CsPb₂Br₅ QDs were tuned from 500to 519 nm.Efficient green photoluminescence of CsPb₂Br₅ QDs glasses can be observed under ultraviolet or blue light exciation.?2?In the same way,We also successfully prepared CsPb₂Br₅ QDs incorporated into glass under various durations of heat-treatment at420°C.Under various durations of heat-treatment at 420°C,PL spectra of CsPb₂Br₅ QDs were tuned from 499 to 506 nm,The CsPb₂Br₅ glass showed an thermal stability with about 85%emission loss when elevating temperature from 298 K to 433 K.Moreover,The CsPb₂Br₅ QDs in glasses exhibits excellent optical performance and good thermal and photostability so that the warm white light emitting diodes?WLEDs?was realized through incorporating CaAlSiN₃:Eu²⁺red phosphor with CsPb₂Br₅ QDs doped borosilicate glasses on an InGaN blue chip.This work opens up the exciting opportunity of using all-inorganic CsPb₂Br₅QDs for high performance and low-cost WLEDs applications.?3?The composition of blue agate and its optical properties were investigated.Al and K are two main trace elements in the blue agate samples,which have up to 466 ppm and 182 ppm.Cu element was detected by ICP-OES analysis,which is the main reason why the agate appears blue.The specimen was also characterized by UV-vis,Z-scan,aiming to study the third-order nonlinear optical?NLO?properties.The nonlinear refractive index and absorption coefficient of the sample was measured to be 1.39×10^-18 m²/W and 6.94×10^-13 m/W,respectively.Therefore,the third-order NLO susceptibility was calculated to be1.45×10^-12esu,demonstrating an excellent third-order NLO response of the blue agate sample.