scholarly journals Germanium-lead perovskite light-emitting diodes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dexin Yang ◽  
Guoling Zhang ◽  
Runchen Lai ◽  
Yao Cheng ◽  
Yaxiao Lian ◽  
...  
Keyword(s):  
Environmental Impact ◽  
High Performance ◽  
High Brightness ◽  
Light Emitting ◽  
Perovskite Materials ◽  
Promising Solution ◽  
Halide Perovskites ◽  
Reduced Toxicity ◽  
Photovoltaic Solar Cells ◽  
Lead Halide

AbstractReducing environmental impact is a key challenge for perovskite optoelectronics, as most high-performance devices are based on potentially toxic lead-halide perovskites. For photovoltaic solar cells, tin-lead (Sn–Pb) perovskite materials provide a promising solution for reducing toxicity. However, Sn–Pb perovskites typically exhibit low luminescence efficiencies, and are not ideal for light-emitting applications. Here we demonstrate highly luminescent germanium-lead (Ge–Pb) perovskite films with photoluminescence quantum efficiencies (PLQEs) of up to ~71%, showing a considerable relative improvement of ~34% over similarly prepared Ge-free, Pb-based perovskite films. In our initial demonstration of Ge–Pb perovskite LEDs, we achieve external quantum efficiencies (EQEs) of up to ~13.1% at high brightness (~1900 cd m−2), a step forward for reduced-toxicity perovskite LEDs. Our findings offer a new solution for developing eco-friendly light-emitting technologies based on perovskite semiconductors.

Tunable ultra-uniform Cs4PbBr6 perovskites with efficient photoluminescence and excellent stability for high-performance white light-emitting diodes

2021 ◽  
Author(s):  
Yao Li ◽  
Kaimin Du ◽  
Manli Zhang ◽  
Xuan Gao ◽  
Yu Lu ◽  
...  
Keyword(s):  
White Light ◽  
High Performance ◽  
Light Emitting Diodes ◽  
Metal Halide ◽  
Light Emitting ◽  
New Class ◽  
Halide Perovskites ◽  
White Light Emitting Diodes ◽  
Lead Halide ◽  
Excellent Stability

Metal halide perovskites are a new class of promising materials in optoelectronic applications. As optoelectronic properties of the lead halide perovskites are determined largely by their morphology, the morphology of...

scholarly journals Bandgap tuning strategy by cations and halide ions of lead halide perovskites learned from machine learning

RSC Advances ◽  
2021 ◽  
Vol 11 (26) ◽  
pp. 15688-15694
Author(s):  
Yaoyao Li ◽  
Yao Lu ◽  
Xiaomin Huo ◽  
Dong Wei ◽  
Juan Meng ◽  
...  
Keyword(s):  
Perovskite Solar Cells ◽  
Halide Ions ◽  
Bandgap Engineering ◽  
Light Emitting ◽  
Perovskite Materials ◽  
Color Tunable ◽  
Halide Perovskites ◽  
Tuning Strategy ◽  
Bandgap Tuning ◽  
Lead Halide

Bandgap engineering of lead halide perovskite materials is critical to achieve highly efficient and stable perovskite solar cells and color tunable stable perovskite light-emitting diodes.

scholarly journals High-performance quasi-2D perovskite light-emitting diodes: from materials to devices

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Li Zhang ◽  
Changjiu Sun ◽  
Tingwei He ◽  
Yuanzhi Jiang ◽  
Junli Wei ◽  
...  
Keyword(s):  
Energy Transfer ◽  
High Performance ◽  
Light Emitting Diodes ◽  
Structural Characteristics ◽  
Quantum Yields ◽  
Research Directions ◽  
Light Emitting ◽  
Perovskite Materials ◽  
Quantum Confinement Effects ◽  
Semiconducting Properties

AbstractQuasi-two-dimensional (quasi-2D) perovskites have attracted extraordinary attention due to their superior semiconducting properties and have emerged as one of the most promising materials for next-generation light-emitting diodes (LEDs). The outstanding optical properties originate from their structural characteristics. In particular, the inherent quantum-well structure endows them with a large exciton binding energy due to the strong dielectric- and quantum-confinement effects; the corresponding energy transfer among different n-value species thus results in high photoluminescence quantum yields (PLQYs), particularly at low excitation intensities. The review herein presents an overview of the inherent properties of quasi-2D perovskite materials, the corresponding energy transfer and spectral tunability methodologies for thin films, as well as their application in high-performance LEDs. We then summarize the challenges and potential research directions towards developing high-performance and stable quasi-2D PeLEDs. The review thus provides a systematic and timely summary for the community to deepen the understanding of quasi-2D perovskite materials and resulting LED devices.

scholarly journals Recent advancements and perspectives on light management and high performance in perovskite light-emitting diodes

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shaoni Kar ◽  
Nur Fadilah Jamaludin ◽  
Natalia Yantara ◽  
Subodh G. Mhaisalkar ◽  
Wei Lin Leong
Keyword(s):  
High Performance ◽  
Light Propagation ◽  
Light Emission ◽  
Review Article ◽  
Rapid Progress ◽  
Light Emitting ◽  
Materials Engineering ◽  
Perovskite Materials ◽  
Light Management ◽  
Photon Recycling

Abstract Perovskite semiconductors have experienced meteoric rise in a variety of optoelectronic applications. With a strong foothold on photovoltaics, much focus now lies on their light emission applications. Rapid progress in materials engineering have led to the demonstration of external quantum efficiencies that surpass the previously established theoretical limits. However, there remains much scope to further optimize the light propagation inside the device stack through careful tailoring of the optical processes that take place at the bulk and interface levels. Photon recycling in the emitter material followed by efficient outcoupling can result in boosting external efficiencies up to 100%. In addition, the poor ambient and operational stability of these materials and devices restrict further commercialization efforts. With best operational lifetimes of only a few hours reported, there is a long way to go before perovskite LEDs can be perceived as reliable alternatives to more established technologies like organic or quantum dot-based LED devices. This review article starts with the discussions of the mechanism of luminescence in these perovskite materials and factors impacting it. It then looks at the possible routes to achieve efficient outcoupling through nanostructuring of the emitter and the substrate. Next, we analyse the instability issues of perovskite-based LEDs from a photophysical standpoint, taking into consideration the underlying phenomena pertaining to defects, and summarize recent advances in mitigating the same. Finally, we provide an outlook on the possible routes forward for the field and propose new avenues to maximally exploit the excellent light-emitting capabilities of this family of semiconductors.

scholarly journals High-performance large-area quasi-2D perovskite light-emitting diodes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Changjiu Sun ◽  
Yuanzhi Jiang ◽  
Minghuan Cui ◽  
Lu Qiao ◽  
Junli Wei ◽  
...  
Keyword(s):  
High Performance ◽  
Light Emitting Diodes ◽  
Intermediate Phase ◽  
Formation Enthalpy ◽  
Phase Segregation ◽  
Phase Changes ◽  
Large Area ◽  
High Brightness ◽  
Light Emitting ◽  
Performance Decline

AbstractSerious performance decline arose for perovskite light-emitting diodes (PeLEDs) once the active area was enlarged. Here we investigate the failure mechanism of the widespread active film fabrication method; and ascribe severe phase-segregation to be the reason. We thereby introduce L-Norvaline to construct a COO−-coordinated intermediate phase with low formation enthalpy. The new intermediate phase changes the crystallization pathway, thereby suppressing the phase-segregation. Accordingly, high-quality large-area quasi-2D films with desirable properties are obtained. Based on this, we further rationally adjusted films’ recombination kinetics. We reported a series of highly-efficient green quasi-2D PeLEDs with active areas of 9.0 cm2. The peak EQE of 16.4% is achieved in <n > = 3, represent the most efficient large-area PeLEDs yet. Meanwhile, high brightness device with luminance up to 9.1 × 104 cd m−2 has achieved in <n> = 10 film.

scholarly journals Lead-Free Halide Double Perovskites: A Review of the Structural, Optical, and Stability Properties as Well as Their Viability to Replace Lead Halide Perovskites

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 667 ◽  
Author(s):  
Edson Meyer ◽  
Dorcas Mutukwa ◽  
Nyengerai Zingwe ◽  
Raymond Taziwa
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Lead Free ◽  
Double Perovskites ◽  
Stability Properties ◽  
Perovskite Materials ◽  
Halide Perovskites ◽  
Halide Perovskite ◽  
Light Absorbers ◽  
Lead Halide

Perovskite solar cells employ lead halide perovskite materials as light absorbers. These perovskite materials have shown exceptional optoelectronic properties, making perovskite solar cells a fast-growing solar technology. Perovskite solar cells have achieved a record efficiency of over 20%, which has superseded the efficiency of Gräztel dye-sensitized solar cell (DSSC) technology. Even with their exceptional optical and electric properties, lead halide perovskites suffer from poor stability. They degrade when exposed to moisture, heat, and UV radiation, which has hindered their commercialization. Moreover, halide perovskite materials consist of lead, which is toxic. Thus, exposure to these materials leads to detrimental effects on human health. Halide double perovskites with A2B′B″X6 (A = Cs, MA; B′ = Bi, Sb; B″ = Cu, Ag, and X = Cl, Br, I) have been investigated as potential replacements of lead halide perovskites. This work focuses on providing a detailed review of the structural, optical, and stability properties of these proposed perovskites as well as their viability to replace lead halide perovskites. The triumphs and challenges of the proposed lead-free A2B′B″X6 double perovskites are discussed here in detail.

scholarly journals Origin of unusual bandgap shift and dual emission in organic-inorganic lead halide perovskites

2016 ◽  
Vol 2 (10) ◽  
pp. e1601156 ◽  
Author(s):  
M. Ibrahim Dar ◽  
Gwénolé Jacopin ◽  
Simone Meloni ◽  
Alessandro Mattoni ◽  
Neha Arora ◽  
...  
Keyword(s):  
Density Functional ◽  
Valence Band Maximum ◽  
Dual Emission ◽  
Time Resolved ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Perovskite Materials ◽  
Halide Perovskites ◽  
Dynamics Simulations ◽  
Increasing Temperature

Emission characteristics of metal halide perovskites play a key role in the current widespread investigations into their potential uses in optoelectronics and photonics. However, a fundamental understanding of the molecular origin of the unusual blueshift of the bandgap and dual emission in perovskites is still lacking. In this direction, we investigated the extraordinary photoluminescence behavior of three representatives of this important class of photonic materials, that is, CH3NH3PbI3, CH3NH3PbBr3, and CH(NH2)2PbBr3, which emerged from our thorough studies of the effects of temperature on their bandgap and emission decay dynamics using time-integrated and time-resolved photoluminescence spectroscopy. The low-temperature (<100 K) photoluminescence of CH3NH3PbI3and CH3NH3PbBr3reveals two distinct emission peaks, whereas that of CH(NH2)2PbBr3shows a single emission peak. Furthermore, irrespective of perovskite composition, the bandgap exhibits an unusual blueshift by raising the temperature from 15 to 300 K. Density functional theory and classical molecular dynamics simulations allow for assigning the additional photoluminescence peak to the presence of molecularly disordered orthorhombic domains and also rationalize that the unusual blueshift of the bandgap with increasing temperature is due to the stabilization of the valence band maximum. Our findings provide new insights into the salient emission properties of perovskite materials, which define their performance in solar cells and light-emitting devices.

Improvement of efficiency and its roll-off at high brightness in white organic light-emitting diodes by strategically managing triplet excitons in the emission layer

2018 ◽  
Vol 6 (40) ◽  
pp. 10793-10803 ◽  
Author(s):  
Shian Ying ◽  
Dezhi Yang ◽  
Xianfeng Qiao ◽  
Yanfeng Dai ◽  
Qian Sun ◽  
...  
Keyword(s):  
High Performance ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Emission Layer ◽  
High Brightness ◽  
Light Emitting ◽  
Organic Light ◽  
Low Efficiency ◽  
Triplet Excitons

High-performance WOLEDs realizing high efficiency and low efficiency roll-off simultaneously were achieved by strategically managing triplet excitons in the emission layer.

scholarly journals Regulating off-centering distortion maximizes photoluminescence in halide perovskites

2020 ◽  
Author(s):  
Xujie Lü ◽  
Constantinos Stoumpos ◽  
Qingyang Hu ◽  
Xuedan Ma ◽  
Dongzhou Zhang ◽  
...  
Keyword(s):  
High Pressure ◽  
High Performance ◽  
Quantitative Relationship ◽  
External Pressure ◽  
Structural Distortion ◽  
Diagnostic Tools ◽  
Light Emitting ◽  
Universal Relationship ◽  
Halide Perovskites ◽  
Use Of Knowledge

Abstract Metal halide perovskites possess unique atomic and electronic configurations that endow them with high defect tolerance and enable high-performance photovoltaics and optoelectronics[1–3]. Perovskite light-emitting diodes have achieved an external quantum efficiency of over 20%[4–5]. Despite tremendous progress, fundamental questions remain, such as how structural distortion affects the optical properties. Addressing their relationships is considerably challenging due to the scarcity of effective diagnostic tools during structural and property tuning as well as the limited tunability achievable by conventional methods. Here, using pressure and chemical methods to regulate the metal off-centering distortion, we demonstrate the giant tunability of photoluminescence (PL) in both the intensity (&gt;20 times) and wavelength (&gt;180 nm/GPa) in the highly-distorted halide perovskites [CH3NH3GeI3, HC(NH2)2GeI3, and CsGeI3]. Using advanced in situ high-pressure probes and first-principles calculations, we quantitatively reveal a universal relationship whereby regulating the level of off-centering distortion towards 0.2 leads to the best PL performance in the halide perovskites. By applying this principle, intense PL can still be induced by substituting CH3NH3+ with Cs+ to control the distortion in (CH3NH3)1-xCsxGeI3, where the chemical substitution plays a similar role as external pressure. The compression of a fully substituted sample of CsGeI3 further tunes the distortion to the optimal value at 0.7 GPa, which maximizes the emission with a ten-fold enhancement. This work not only demonstrates a quantitative relationship between structural distortion and PL property of the halide perovskites but also illustrates the use of knowledge gained from high-pressure research to achieve the desired properties by ambient methods.

scholarly journals Directional and Fast Photoluminescence from CsPbI3 Nanocrystals Coupled to Dielectric Circular Bragg Gratings

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 422
Author(s):  
Yan Hua ◽  
Yuming Wei ◽  
Bo Chen ◽  
Zhuojun Liu ◽  
Zhe He ◽  
...  
Keyword(s):  
High Performance ◽  
Emission Rate ◽  
Bragg Gratings ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Radiative Emission ◽  
Nanophotonic Devices ◽  
Device Applications ◽  
Fundamental Research ◽  
Lead Halide

Lead halide perovskite nanocrystals (NCs), especially the all-inorganic perovskite NCs, have drawn substantial attention for both fundamental research and device applications in recent years due to their unique optoelectronic properties. To build high-performance nanophotonic devices based on perovskite NCs, it is highly desirable to couple the NCs to photonic nanostructures for enhancing the radiative emission rate and improving the emission directionality of the NCs. In this work, we synthesized high-quality CsPbI3 NCs and further coupled them to dielectric circular Bragg gratings (CBGs). The efficient couplings between the perovskite NCs and the CBGs resulted in a 45.9-fold enhancement of the photoluminescence (PL) intensity and 3.2-fold acceleration of the radiative emission rate. Our work serves as an important step for building high-performance nanophotonic light emitting devices by integrating perovskite NCs with photonic nanostructures.

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