Enhanced Stability and Tunable Photoluminescence in Perovskite CsPbX₃/ZnS Quantum Dot Heterostructure

Abstract

All-inorganic perovskite CsPbX (X = Cl, Br, I) and related materials are promising candidates for potential solar cells, light emitting diodes, and photodetectors. Here, a novel architecture made of CsPbX /ZnS quantum dot heterodimers synthesized via a facile solution-phase process is reported. Microscopic measurements show that CsPbX /ZnS heterodimer has high crystalline quality with enhanced chemical stability, as also evidenced by systematic density functional theory based first-principles calculations. Remarkably, depending on the interface structure, ZnS induces either n-type or p-type doping in CsPbX and both type-I and type-II heterojunctions can be achieved, leading to rich electronic properties. Photoluminescence measurement results show a strong blue-shift and decrease of recombination lifetime with increasing sulfurization, which is beneficial for charge diffusion in solar cells and photovoltaic applications. These findings are expected to shed light on further understanding and design of novel perovskite heterostructures for stable, tunable optoelectronic devices.

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

“…The integrating procedure was conducted in nonpolar hexane by means of sonication or agitation. [55] The optical photos are shown in the inset of Figure 3b, compared with viscous PQDs capped by oleic acid and oleylamine molecules, the HNS-PQDs in a powder form provide much convenience in fabrication of devices. At last, the sample of HNS-PQDs nanocomposites was obtained by centrifugation and dried in vacuum oven at 40 °C (for more details please refer to the Supporting Information).…”

“…Restraining the ion-exchange reactions between different perovskite materials is of real potential to apply these high quantum efficiencies of PQDs as the phosphor for solidstate lighting applications. [32,55] The iodine-containing CsPb(Br x I 1−x ) 3 presents higher sensitivity to moisture in ambient air. 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.…”

Lead Halide Perovskite Nanocrystals in the Research Spotlight: Stability and Defect Tolerance

“…(e) Optical stability of CsPbBr 3– x I x and CsPbBr 3– x I x /ZnS. Adapted from ref (100). Copyright 2017, Wiley Online Library.…”

“…100 Figure 6e compares the PL stabilities for pure CsPbBr 3– x I x and CsPbBr 3– x I x /ZnS heterodimers. The CsPbBr 3– x I x /ZnS heterodimer could keep for about 12 days without any protection in air, while pure CsPbBr 3– x I x QDs became unstable and blue-shifted within 1 day under the same conditions.…”

Single Halide Perovskite/Semiconductor Core/Shell Quantum Dots with Ultrastability and Nonblinking Properties

“…stability, such as by introducing mesoporous silica, [11] intermolecular CC bonding, [12] alkyl phosphate layer, [13] chemical doping, [14] and heterostructures, such as CsPbBr 3 /ZnS heterodimers and CH 3 NH 2 PbX 3 /SiO 2 sphere. [15,16] Also, these materials usually exhibit obvious photoluminescence (PL) blinking at the single-dot level, [15] which is caused by the nonradiative Auger recombination process [17] and has severe detrimental effects on the efficiency of optoelectronic devices based on spontaneous emission (such as LEDs).…”