A General Strategy for In Situ Growth of All‐Inorganic CsPbX₃ (X = Br, I, and Cl) Perovskite Nanocrystals in Polymer Fibers toward Significantly Enhanced Water/Thermal Stabilities

Abstract

Currently, all‐inorganic CsPbX3 (X = Br, I, and Cl) perovskites (IPs) are emerging as excellent candidate materials for exploring optoelectronic devices, due to their superior optical/electronic performances. However, their intrinsic poor stability greatly limits their practical applications. Here, a general strategy is reported for in situ growth of all‐inorganic perovskite nanocrystals (IPNCs) in polymer fibers with highly uniform size and spatial distribution, which is based on one‐step electrospinning of solutions containing IPs precursors and polymers. It is verified that the IPNCs of CsPbX3 can be uniformly encapsulated within the polymer fibers with finely tuned compositions, by rationally adjusting the ratios of PbX2 and CsX salts in the raw solutions. Consequently, the photoluminescence (PL) emissions of CsPbX3@polymer fibers can be readily tuned to cover the whole visible range. The obtained CsPbBr3@polymer fibers exhibit fundamentally improved water/thermal stabilities with a PL quantum yield (QY) of 48%. Their PL QY retains beyond 70% of its original value after being immersed in water for 192 h and maintains over 50% after being heated at 80 °C for 120 min. Furthermore, the light emitting diodes with high brightness based on CsPbBr3@polymer fibers are constructed, suggesting their promising applications.

CsPbBr3‐Quantum‐Dots/Polystyrene@Silica Hybrid Microsphere Structures with Significantly Improved Stability for White LEDs

“…Compared with pure CsPbBr 3 PQDs, the PL lifetimes of both CsPbBr 3 /MPMs and CsPbBr 3 /MPMs@SiO 2 are relatively prolonged. This phenomenon may be assigned to the encapsulation and passivation effects provided by the polymer microsphere and silica layer, which reduces the surface defect/trap state density of the PQDs and elongates their fluorescence lifetime …”

“…Some protective strategies have been proposed to improve PQDs stability, which can be mainly divided into two viable categories . The first category relies on modifying or strengthening the surface ligand molecules of the PQDs, which can passivate surface defects or dangling bonds, thus improving the material stability .…”

Flexible Linearly Polarized Photodetectors Based on All‐Inorganic Perovskite CsPbI3 Nanowires

“…In addition, light absorption of materials with 1D morphology changes along with polarization direction of incident light, for example, InP and CdSe nanowires have been grown and exhibited stronger light absorption for light with polarization direction in parallel with nanowires, resulting in linearly polarized sensitivity . Combining anisotropic crystal structure and anisotropic morphology simultaneously would realize high linearly polarized sensitivity . Halide perovskites have long carrier lifetime and diffusion length, and have been successfully applied in highly sensitive and fast photodetectors .…”

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…”