Enhancing the Stability of Perovskite Quantum Dots by Encapsulation in Crosslinked Polystyrene Beads via a Swelling–Shrinking Strategy toward Superior Water Resistance

Abstract

Organic/inorganic hybrid lead halide perovskites are promising optoelectronic materials due to their unique structure, excellent properties, and fascinating potential applications in lighting, photovoltaic, etc. However, perovskite materials are very sensitive to moisture and polar solvent, which greatly hinders their practical applications. Here, highly luminescent perovskite-polystyrene composite beads with uniform morphology are prepared via a simple swelling-shrinking strategy. This process is carried out only in nonpolar toluene and hexane without the addition of any polar reagents. As a result, the as-prepared composite beads not only retain high luminescence but also exhibit superior water-resistant property. The composites emit strong luminescence after being immersed into water over nine months. Moreover, even in some harsh environments such as acid/alkali aqueous solution, phosphate buffer solution, and Dulbecco's modified eagle medium biological buffers, they still preserve high luminescence. The applications in light-emitting diodes and cellular labeling agents are also carried out to demonstrate their ultrastability.

Spray‐Assisted Coil–Globule Transition for Scalable Preparation of Water‐Resistant CsPbBr3@PMMA Perovskite Nanospheres with Application in Live Cell Imaging

“…The fluorescence intensity of CPB PQD colloid declined nearly 100% within 1 h in case of either water or ethanol, as shown in Figure a. Meanwhile, the CPB@PMMA nanospheres retained stable fluorescence intensities over the 80 days of this study in both water and ethanol, with the intensity loss of only 19% and 8%, respectively, comparable to literatures …”

Highly Luminescent Lead Halide Perovskite Quantum Dots in Hierarchical CaF2 Matrices with Enhanced Stability as Phosphors for White Light‐Emitting Diodes

“…It can be seen from the spectrum of the resulting device (Figure 4a), three discrete emission peaks located at 442, 520, and 621 nm were observed. And the as-prepared composites [28,36,37,40,42,46,47,51,53] could act as the green phosphors with decent performance. The selected triangle of blue, green, and red monochromatic light covers 130% of the National Television System Committee (NTSC) standard, which indicates great potential application in white backlights for LCDs.…”

“…[30][31][32] The crystal structure of lead halide perovskite would be easily destroyed when they are exposed in the ambient air, which leads to fluorescence quenching and then decreasing the electro-optical conversion efficiency of devices. [35][36][37][38][39][40][41] Indeed, the Lead halide perovskite quantum dots (PQDs) have been widely recognized as highly luminescent materials for efficient optoelectronic applications owing to their fascinating electronic and optical properties. [34] In general, the dense polymer chains could passivate the surface of perovskite as well as protect them from contacting with environment directly.…”

“…[39][40][41][42] However, suffering from the poor thermal stability of organic components, polymers do not seem to be the best choice to protect PQDs. Especially, the obtained perovskite-polymer composites display waterproof property whereas the pristine perovskite materials are highly sensitive to humidity.…”

Highly Efficient and Water‐Stable Lead Halide Perovskite Quantum Dots Using Superhydrophobic Aerogel Inorganic Matrix for White Light‐Emitting Diodes

“…While protected PQDs with high chemical, thermal, and irradiation stabilities have been obtained, [28] the water stability of PQDs prepared with these inorganic shells still indicate a lot of room for improvement. [18,19,[31][32][33][34][35][36][37][38][39] The hydrophobic surface and dense polymer chains of the matrix can effectively protect the PQDs from the external environment, considerably enhancing their [18,19,[31][32][33][34][35][36][37][38][39] The hydrophobic surface and dense polymer chains of the matrix can effectively protect the PQDs from the external environment, considerably enhancing their…”