Morphology controlled nanocrystalline CsPbBr3 thin-film for metal halide perovskite light emitting diodes

The Perovskite Optoelectronic Devices - A Look at the Future

The perovskite materials are broadly incorporated into optoelectronic devices due to a number of advantages. Their rapid technological progress is related to the relatively simple fabrication process, low production cost and high efficiency. Significant improvement is made in the light emitting, detection performance and device design especially operating in the visible and near-infrared regions. This review presents the status and possible future development of the perovskite devices such as solar cells, photodetectors, and light-emitting diodes. The fundamental properties of perovskite materials related to their effective device applications are summarized. Since the development of the perovskite technology is mainly driven by the revolutionary evolution of the semiconductor perovskite solar cell as a robust candidate for next-generation solar energy harvesting, this topic is considered first. The device engineering of various perovskite photodetector structures, including perovskite quantum dot photodetectors, is then discussed in detail. Their performance is compared with the current commercial photodetectors available on the global market together with their challenges. Finally, the considerable progress in the fabrication of the perovskite light-emitting diodes with external quantum efficiency exceeding 20% is presented. The paper is completed in an attempt to determine the development of perovskite optoelectronic devices in the future.

Supersaturated Antisolvent-Assisted Crystallization for Highly Efficient Inorganic Perovskite Light-Emitting Diodes

We introduced a strategy to form nanocrystalline CsPbBr3 perovskite films with high luminescence and stability, inhibiting crystal growth using a CsBr supersaturated antisolvent during the antisolvent-assisted crystallization process. We devised this strategy because the supersaturated antisolvent has a higher CsBr concentration over its solubility limit in the saturated antisolvent and consequently will form the smaller perovskite nanocrystalline grains due to the quick precipitation of the CsBr. Here, the CsBr is chosen as a model inorganic antisolvent additive for a crystal growth inhibitor and a passivator. Consequently, we have achieved a nanocrystalline CsPbBr3 film with an average grain size of ∼39 nm by the CsBr supersaturated antisolvent-assisted crystallization process, which is about 41% smaller than the average grain size of the control sample. Hence, the perovskite thin film exhibited a much higher photoluminescence quantum yield than the control film. The maximum current efficiency (CEmax) and the maximum external quantum efficiency (EQEmax) of the corresponding CsPbBr3 perovskite light-emitting diodes (PeLEDs) were approximately twice higher (CEmax of 94.64 cd A-1 and EQEmax of 22.93%) than those of the control device. Simultaneously, the inclusion of CsBr additives played a multifunctional role in diminishing the leakage current of PeLEDs and enhancing their operational lifetime.

Diffusion-Controlled Crystal Engineering with Diverse Antisolvent Intervention for the Preparation of High-Quality Hybrid Perovskite Films

Antisolvent engineering is routinely used to modulate the crystallization of perovskite films as they can offer an additional driving force for nucleation. Actually, the intervention of antisolvent into nucleation is thought to involve some relatively fast and complex processes, which, however, are not fully understood so far. Here, the diffusion of the organic amine cation FA+ (one dominated precursor) and its distribution in a spin-coating process in different antisolvents is simulated by the computational fluid dynamics (CFD) model. It is suggested that a moderate diffusion rate (like that in the case of toluene as an antisolvent) not only enables to form a very uniform distribution of FA+ ions on the substrate, beneficial to the uniform nucleation of the intermediate phase, but also can balance the nucleation and growth rates of the intermediate phase, thereby suppressing undesired heterogeneous nucleation and growth. Results show that the perovskite film fabricated using toluene as an antisolvent has a high quality, based on which higher power conversion efficiencies of up to 24.32% are achieved for perovskite solar cells.

Recent Advances in Patterning Strategies for Full-Color Perovskite Light-Emitting Diodes

Metal halide perovskites have emerged as promising light-emitting materials for next-generation displays owing to their remarkable material characteristics including broad color tunability, pure color emission with remarkably narrow bandwidths, high quantum yield, and solution processability. Despite recent advances have pushed the luminance efficiency of monochromic perovskite light-emitting diodes (PeLEDs) to their theoretical limits, their current fabrication using the spin-coating process poses limitations for fabrication of full-color displays. To integrate PeLEDs into full-color display panels, it is crucial to pattern red-green-blue (RGB) perovskite pixels, while mitigating issues such as cross-contamination and reductions in luminous efficiency. Herein, we present state-of-the-art patterning technologies for the development of full-color PeLEDs. First, we highlight recent advances in the development of efficient PeLEDs. Second, we discuss various patterning techniques of MPHs (i.e., photolithography, inkjet printing, electron beam lithography and laser-assisted lithography, electrohydrodynamic jet printing, thermal evaporation, and transfer printing) for fabrication of RGB pixelated displays. These patterning techniques can be classified into two distinct approaches: in situ crystallization patterning using perovskite precursors and patterning of colloidal perovskite nanocrystals. This review highlights advancements and limitations in patterning techniques for PeLEDs, paving the way for integrating PeLEDs into full-color panels.

Potential and perspectives of halide perovskites in light emitting devices

Light emitting diodes (LEDs) have become part of numerous electrical and electronic systems such as lighting, displays, status indicator lamps and wearable electronics. Owing to their excellent optoelectronic properties and deposition via simple solution process, metal halide perovskites possess unique potential for developing halide perovskite-based LEDs (PeLEDs) with superior photoluminescence efficiencies leading to external quantum efficiencies beyond 20% for PeLEDS. However, the limited durability, high operative voltages, and challenges of scale-up are persisting barriers in achieving required technology readiness levels. To build up the existing knowledge and raise the device performance this review provides a state-of-the-art study on the properties, film and device fabrication, efficiency, and stability of PeLEDs. In terms of commercialization, PeLEDs need to overcome materials and device challenges including stability, ion migration, phase segregation, and joule heating, which are discussed in this review. We hope, discussions about the strategies to overcome the stability issues and enhancement the materials intrinsic properties towards development more stable and efficient optoelectronic devices can pave the way for scalability and cost-effective production of PeLEDs.

CsPbBr3-DMSO merged perovskite micro-bricks for efficient X-ray detection

Inorganic perovskite wafers with good stability and adjustable sizes are promising in X-ray detection but the high synthetic temperature is a hindrance. Herein, dimethyl sulfoxide (DMSO) is used to prepare the CsPbBr3 micro-bricks powder at room temperature. The CsPbBr3 powder has a cubic shape with few crystal defects, small charge trap density, and high crystallinity. A trace amount of DMSO attaches to the surface of the CsPbBr3 micro-bricks via Pb-O bonding, forming the CsPbBr3-DMSO adduct. During hot isostatic processing, the released DMSO vapor merges the CsPbBr3 micro-bricks, producing a compact and dense CsPbBr3 wafer with minimized grain boundaries and excellent charge transport properties. The CsPbBr3 wafer shows a large mobility-lifetime (μτ) product of 5.16 × 10-4 cm2·V-1, high sensitivity of 14,430 μC·Gyair-1·cm-2, low detection limit of 564 nGyair·s-1, as well as robust stability in X-ray detection. The results reveal a novel strategy with immense practical potential pertaining to high-contrast X-ray detection.

Electronic Supplementary Material

Supplementary material (further details of the characterization, SEM images, AFM images, KPFM images, schematic illustration, XRD patterns, XPS spectra, FTIR spectra, UPS spectra, and stability tests) is available in the online version of this article at 10.1007/s12274-023-5487-3.

Three-Color White Photoluminescence Emission Using Perovskite Nanoplatelets and Organic Emitter

Three organic blue-light-emitting tetraphenylethylene (TPE) derivatives that exhibit aggregation-induced emission (AIE) were used as additives in the preparation of inorganic perovskite-structured green-light-emitting materials for three-color white-light emission. For these organic–inorganic light-emitting materials, two-color (blue and green) light-emitting films based on the CsPbBr₃ perovskite-structured green-light-emitting inorganic material were prepared. The three TPE derivatives were prepared by varying the number of bromide groups, and a distinct AIE effect was confirmed when the derivatives were dissolved in a water–tetrahydrofuran mixed solvent containing 90 vol% water. When 0.2 molar ratio of the 1,1,2,2-tetrakis(4-bromophenyl)ethylene (TeBrTPE) additive was mixed with nanocrystal-pinning toluene solvent, the green-light-emission photoluminescence quantum efficiency (PLQY) value at 535 nm was 47 times greater than that of the pure bulk CsPbBr₃ without additives and a blue emission at 475 nm was observed from the TeBrTPE itself. When a CBP:Ir(piq)₃ film was prepared on top of this layer, three PL peaks with maximum wavelength values of 470, 535, and 613 nm were confirmed. The film exhibited white-light emission with CIE color coordinates of (0.25, 0.36).