Cesium lead halide perovskite quantum dots (CsPbX3) have emerged as pivotal materials in the realm of optoelectronics, owing to their exceptional properties. However, traditional synthesis methods often yield quantum dots (QDs) with poor durability, rendering them susceptible to degradation under various environmental impact such as light, oxygen, humidity, and high temperatures. This inherent instability hampers their long-term viability across diverse applications.
1) Stability Challenges and Solutions When exposed to adverse conditions, colloidal CsPbX3 QDs swiftly deteriorate, leading to a decline in their photoluminescence (PL) emission performance. To mitigate this issue, diverse strategies have been devised,focusing on enhancing the long-term durability of QDs. Such as surface ligand modification, mesoporous structure encapsulation, core-shell structures, and composition engineering: Despite these advancements, challenges persist, particularly regarding the efficacy of surface protective layers. Existing methods often yield structures with insufficient density, leading to compromised long-term protection. Additionally, the stability of silicon dioxide, commonly utilized in wet chemical methods, remains a concern. The protective layer structure formed by these methods on the surface of PQDs is not dense, and the silicon dioxide prepared by wet chemical methods is also unstable, making the long-term protection of PQDs insufficient against external environmental factors.
2) Quantum Dots Glass: A Solution for Long-Term Stability Inorganic glass is considered an excellent medium to prevent QDs degradation and improve their thermal stability. For example, there have been reports on the growth of II-VI and IV-VI QDs in glass,such as ZnO, ZnS, ZnSe, CdS, CdSe, PbS, and PbSe. Studies have found that glass has chemical and physical stability, as well as high mechanical strength, high temperature resistance, and chemical corrosion resistance. Glasses can prevent QDs from being eroded by the surrounding environment, allowing QDs to be evenly distributed in the glass matrix without aggregation, and the size of QDs embedded in glass is easy to control. Hence, a novel approach to address the stability issues of CsPbX3 QDs involves embedding them within a structurally dense and performance-stable inert glass matrix, creating what is known as “quantum dots glass.” This innovative composite material effectively circumvents the drawbacks associated with poor stability in standalone QDs while preserving their exceptional performance characteristics.
3) Expanding Horizons with Quantum Dots Glass Quantum dots glass not only offers enhanced stability but unlocks new possibilities in optoelectronic applications as well. Beyond addressing stability concerns, quantum dots glass holds promise for diverse applications, including:
Optical Fiber Fabrication: Leveraging the properties of quantum dots glass opens avenues for the fabrication of high-performance optical fibers, facilitating advancements in telecommunications and photonics.
Optoelectronic Functional Materials: By integrating quantum dots glass into optoelectronic devices, novel functionalities and performance enhancements can be achieved, paving the way for next-generation technologies.
Summary and prospects In this paper, we delve into the preparation methods, crystallization, and emission mechanisms of cesium lead halide quantum dots glass. Emphasis is placed on the stability challenges encountered in practical applications, including temperature variations, light exposure, and humidity. Significant strides in addressing these challenges are highlighted, offering insights into potential avenues for future research endeavors.
At the same time, quantum dots glass retains the excellent optical performance of CsPbX3 PQDs. Studies have shown that enhancing the rigidity of the glass network structure, such as replacing GeO4 tetrahedra with SiO4 tetrahedra, helps enhancing the water resistance of quantum dots glass. Additionally, using tellurite-based glasses with a higher density to encapsulate QDs or doping with high atomic number rare earth ions, such as Gd3+ and Lu3+, contributes to improve the material's radiation resistance. However,the understanding of the damage mechanism of PQDs glass under high energy beam irradiation, the thermal erasure mechanism, and the PL quenching mechanism of quantum dots glass at high temperatures is not deep enough at present. There is an urgent need for more direct experimental and theoretical research.
The development of quantum dots glass represents a significant leap forward in enhancing the long-term stability of CsPbX3 QDs. With the in-depth study of the synthesis process of quantum dots glass, by designing rational glass compositions and regulating the precipitation process of CsPbX3 PQDs, comprehensive optimization of optical performance can be achieved. By harnessing the unique properties of both QDs and glass matrices, this composite material not only overcomes stability limitations but also opens new frontiers in optoelectronics. It provides new perspectives for improving the current state of quantum dots glass and is expected to play a crucial role in various optical fields. Moving forward, continued research and innovation in this field hold immense potential for revolutionizing optoelectronic device design and functionality.