Vacuum‐Processed Metal Halide Perovskite Light‐Emitting Diodes: Prospects and Challenges

Bhaumik, Saikat; Kar, Manav R.; Thorat, Bhaskar N.; Bruno, Annalisa; Mhaisalkar, Subodh

doi:10.1002/cplu.202000795

Cited by 13 publications

(11 citation statements)

References 83 publications

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“…[ 6,7 ] Since the first room‐temperature perovskite light‐emitting diodes (PeLEDs) were demonstrated in 2014 with external quantum efficiencies (EQEs) of 0.76% and 0.1%, [ 8 ] the field of PeLEDs has developed rapidly. Due to advances in material composition designs (e.g., mixed cation or anion compositions, metal doping, ligand engineering, and dimensional tuning), [ 9–13 ] control of perovskite formation conditions (e.g., by using additives, solvent treatment, annealing, or vacuum deposition), [ 14,15 ] optimization of device architectures (e.g., development of charge‐transport layers (CTLs) and light out‐coupling structures), [ 16,17 ] and interfacial modification (e.g., buffer layers, blocking layers, interfacial passivation), [ 18,19 ] the record EQEs of PeLEDs have reached 12.3%, [ 20 ] 28.1%, [ 21 ] 23%, [ 22 ] and 22.2% [ 23 ] for blue, green, red, and infrared emission, respectively. Despite the remarkable progress in improving the performance of PeLEDs, the devices still suffer from poor operational stability and rapid decay over time.…”

Section: Introductionmentioning

confidence: 99%

Ion Migration in Perovskite Light‐Emitting Diodes: Mechanism, Characterizations, and Material and Device Engineering

et al. 2022

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sivation), [18,19] the record EQEs of PeLEDs have reached 12.3%, [20] 28.1%, [21] 23%, [22] and 22.2% [23] for blue, green, red, and infrared emission, respectively. Despite the remarkable progress in improving the performance of PeLEDs, the devices still suffer from poor operational stability and rapid decay over time. Although encapsulation of the devices can protect them against moisture and oxygen, [24] internal heat-or electric field-driven defect generation processes, which are often linked to ion migration, could cause severe degradation of electroluminescence.Ion motion in MHPs was initially observed in perovskite solar cells (PSCs) and manifested as an anomalous dielectric response at low frequency and hysteresis in the current-voltage curve. [25] Extensive studies have been performed to investigate the properties of the ions, [25,26] the ion distribution in PSCs under dark and illumination, [27] and the electronic-ionic coupling and its impact on device operation. [28] PSCs differ from PeLEDs in that the fabrication of PeLEDs typically involves the use of largely excess organic halide salts; a portion of these halides do not participate in the perovskite lattice but instead reside on the surfaces and grain boundaries, thus inducing additional mobile ions in the PeLEDs. [29][30][31] More importantly, the electric field across the very thin perovskite layer (typically tens of nanometers) in a PeLED is much stronger than the field in a PSC. Because of these factors and the effects of local heating, ion migration has a substantial effect on PeLEDs operation. Indeed, numerous recent studies have reported ion-induced degradation of PeLEDs. [31][32][33][34][35][36] Accordingly, many studies on understanding, characterizing, and preventing ion generation and migration in PeLEDs have been performed in the last few years.Herein, we perform a systematic review of the origin, movement mechanism, characterization, effects on device performance and stability, and management of ion migration in PeLEDs. As presented in Scheme 1, the review begins by introducing the origins of ionic defects by considering the structural, compositional, and processing characteristics of perovskite emissive layers. Then, the transport dynamics of ions are described with a focus on three factors: Migration activation energy, external stimulus (e.g., electric field and Joule heating), and pathways (i.e., bulk vs grain boundaries or surfaces). Third, the characterization approaches for probing ion migration in In recent years, perovskite light-emitting diodes (PeLEDs) have emerged as a promising new lighting technology with high external quantum efficiency, color purity, and wavelength tunability, as well as, low-temperature processability. However, the operational stability of PeLEDs is still insufficient for their commercialization. The generation and migration of ionic species in metal halide perovskites has been widely acknowledged as the primary factor causing the performance degradation of PeLEDs. Herein, this topic is systematically d...

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Section: Introductionmentioning

confidence: 99%

Ion Migration in Perovskite Light‐Emitting Diodes: Mechanism, Characterizations, and Material and Device Engineering

et al. 2022

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“…large-area thin films with high uniformity. Therefore, more efforts should be focused on the exploration of low-cost, flexible, and mass production fabrication techniques, such as compatible all-vacuum thermal evaporation and roll-to-roll (R2R) fabrication techniques (e.g., blade coating, spray coating, and inkjet printing) [179][180][181]. Tang and co-workers [97,182] successfully fabricated flexible green PeLEDs by an all-vacuum evaporation method with an area of 40.2 cm 2 and a favorable EQE of 7.1%, which is the best performance as far as we know.…”

Section: Reviewsmentioning

confidence: 99%

Flexible perovskite light-emitting diodes: Progress, challenges and perspective

Wang

Zhou

et al. 2022

Sci. China Mater.

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Metal halide perovskites with excellent optoelectronic properties and good ductile properties have emerged as promising materials suitable for flexible optoelectronics that can be integrated into portable and wearable display devices, showing great potential for the next generation displays and lighting. Currently, encouraging progress has been witnessed in the field of flexible perovskite lightemitting diodes (PeLEDs), with maximal external quantum efficiencies (EQEs) of over 28%. Herein, we summarize the major breakthroughs in recent years, with the aim of providing a comprehensive review and facilitating the further development of flexible PeLEDs. In addition, the main challenges that hinder the performance and commercialization of flexible PeLED devices are discussed. Finally, a brief perspective and conclusion toward the future opportunities and applications of flexible PeLEDs are provided.

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“…In the last decade, halide perovskites have attracted attention thanks to their peculiar optical properties, making them ideal candidates as active materials for a high number of technological applications. Low-cost fabrication, high bandgap tunability, easy tuning of the composition and promising emission properties, such as high emission quantum yield and optical gain, are appealing characteristics for applications in sensors [ 1 , 2 ], light emitting devices (LEDs, lasers) [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ], optical memories [ 11 ] and solar cells [ 12 , 13 , 14 ]. The first halide perovskite systems were hybrid organic/inorganic, based on methylammonium lead trihalide (MAPbX 3 , with X = Cl, Br, I), but their organic nature leads to chemical instability under UV light, high temperature, humidity and other extreme conditions [ 15 , 16 ].…”

Section: Introductionmentioning

confidence: 99%

Temperature-Dependent Amplified Spontaneous Emission in CsPbBr3 Thin Films Deposited by Single-Step RF-Magnetron Sputtering

et al. 2023

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Due to their high optical efficiency, low-cost fabrication and wide variety in composition and bandgap, halide perovskites are recognized nowadays as real contenders for the development of the next generation of optoelectronic devices, which, among others, often require high quality over large areas which is readily attainable by vacuum deposition. Here, we report the amplified spontaneous emission (ASE) properties of two CsPbBr3 films obtained by single-step RF-magnetron sputtering from a target containing precursors with variable compositions. Both the samples show ASE over a broad range of temperatures from 10 K up to 270 K. The ASE threshold results strongly temperature dependent, with the best performance occurring at about 50 K (down to 100 µJ/cm2), whereas at higher temperatures, there is evidence of thermally induced optical quenching. The observed temperature dependence is consistent with exciton detrapping up to about 50 K. At higher temperatures, progressive free exciton dissociation favors higher carrier mobility and increases trapping at defect states with consequent emission reduction and increased thresholds. The reported results open the way for effective large-area, high quality, organic solution-free deposited perovskite thin films for optoelectronic applications, with a remarkable capability to finely tune their physical properties.

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Vacuum‐Processed Metal Halide Perovskite Light‐Emitting Diodes: Prospects and Challenges

Cited by 13 publications

References 83 publications

Ion Migration in Perovskite Light‐Emitting Diodes: Mechanism, Characterizations, and Material and Device Engineering

Ion Migration in Perovskite Light‐Emitting Diodes: Mechanism, Characterizations, and Material and Device Engineering

Flexible perovskite light-emitting diodes: Progress, challenges and perspective

Temperature-Dependent Amplified Spontaneous Emission in CsPbBr3 Thin Films Deposited by Single-Step RF-Magnetron Sputtering

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