Preparation And Properties Of Fluorescent Glass Films Based On Perovskite Quantum Dot Glasses

All inorganic perovskite（Cs Pb X₃）perovskite nanocrystals are widely studied for their excellent photoelectric properties.However,its inherent instability and toxicity problems limit its application in the field of optoelectronic devices,which also becomes the bottleneck of its development.Traditional hot injection synthesis requires high temperature reaction and inert gas protection,and the operation process is relatively complicated.High PLQY colloidal Cs Pb X₃ nanocrystals（NCs）can be prepared by a variety of preparation methods.However,due to various damages,it is difficult for Cs Pb X₃ NCs to maintain high luminescence performance in the process of purification and application,resulting in a sharp decline in luminescence performance.At present,there is a lack of low-cost and efficient synthesis processes for the preparation of highly luminous,stable PNC solid state materials,such as powders and films.Here,we apply a simple method to improve the stability of Cs Pb X₃ nanocrystals,namely the growth of Cs Pb X₃ quantum dots in the glass site,which is considered to be a promising method for the preparation of ultra-stable PQDs@glass composite materials.Cs Pb X₃@glass（X=Br,Cl/Br）composites have high humidity and thermal stability.Moreover,PIG-based w-LEDs exhibit superior thermal stability over traditional silicon-based（Pi S）w-LEDs.Most PIS-based w-LEDs range in color temperature from 5000-7000 K and vary widely with driving current power.The higher thermal conductivity of Pi G,which facilitates heat loss and thus reduces the probability of non-radiative transitions,is thought to be the main reason.This also demonstrates the potential of Pi G films in flexible optoelectronic luminescence and display devices.The main research contents of this paper are as follows:1.Borosilicate embedded Cs Pb Br₃@glass glass was prepared by traditional high temperature melting and quenching method.Notably,the photoluminescence quantum yield（PLQY）of Cs Pb Br₃@glass reached 88.06%by optimizing the glass composition.Borosilicate glass matrix can not only protect the contact between nanocrystals and the surrounding environment,but also inhibit the escape of lead ions.In addition,tellurate glass has a lower melting point,which can improve the stability of PQDs and reduce the thermal deterioration of red phosphor in the melt.Films composed of Qi G@glass coated with tellurate glass Cs Pb Br₃@glass and red nitride phosphor are used as color conversion materials to construct light-emitting diode（LED）devices that display a wide color gambit（111.92%of National Television System Commission（NTSC））.Secondly,compared with glass ceramic plates,Pi G film is easy to sinter,and its color coordination can be easily controlled by adjusting the ratio of PQDs@glass and phosphor.The Pi G film also has other excellent properties,such as high thermal conductivity and an adjustable high refractive index,which diffuses heat accumulated on the phosphorus layer onto the silicon glass substrate.This work demonstrates the potential of using Qi G@glass films as an efficient color conversion material for white LED and backlit displays.2.Cyan Cs Pb（Cl Br）₃@glass glass has been successfully prepared by traditional fusion-quenching and heat treatment processes in order to compensate for the cyan and yellow sag in LED spectrum.The growth of Cs Pb（Cl Br）₃ PQDs in borosilicate glass was demonstrated by XRD and TEM characterization.The optical properties of Cs Pb（Cl Br）₃@glass glass are studied from the aspects of light absorption,photoluminescence and life.The quantum yield is improved by adjusting each component in the glass.Tellurate glass coated Cs Pb（Cl Br）₃@glass and yellow phosphor（YAG）Qi G@glass films are also used as color conversion materials to construct light-emitting diode（LED）devices.