The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform

Wei Huang - One of the best experts on this subject based on the ideXlab platform.

  • improving the stability of Metal Halide perovskite quantum dots by encapsulation
    Advanced Materials, 2019
    Co-Authors: Junxian Hong, Wei Huang, Xingxing Tang, Rui Zhu, Runfeng Chen
    Abstract:

    Metal Halide perovskite quantum dots (PQDs), with excellent optical properties and spectacular characteristics of direct and tunable bandgaps, strong light-absorption coefficients, high defect tolerance, and low nonradiative recombination rates, are highly attractive for modern optoelectronic devices. However, the stability issue of PQDs remains a critical challenge of this newly emerged material despite the recent rapid progress. Here, the encapsulation strategies to improve the stability of PQDs are comprehensively reviewed. A special emphasis is put on the effects of encapsulation, ranging from the improvement of chemical stability, to the inhibition of light-induced decomposition, to the enhancement of thermal stability. Particular attention is devoted to summarizing the encapsulation approaches, including the sol-gel method, the template method, physical blending, and microencapsulation. The selection principles of encapsulation materials, including the rigid lattice or porous structure of inorganic compounds, the low penetration rate of oxygen or water, as well as the swelling-deswelling process of polymers, are addressed systematically. Special interest is put on the applications of the encapsulated PQDs with improved stability in white light-emitting diodes, lasers, and biological applications. Finally, the main challenges in encapsulating PQDs and further investigation directions are discussed for future research to promote the development of stable Metal Halide perovskite materials.

  • Metal Halide perovskites: stability and sensing-ability
    Journal of Materials Chemistry C, 2018
    Co-Authors: Zhaohua Zhu, Qian Sun, Zhipeng Zhang, Jie Dai, Guichuan Xing, Xiao Huang, Wei Huang
    Abstract:

    Metal Halide perovskites have been intensively studied over the past years due to their attractive electronic, optical and optoelectronic properties. In spite of the phenomenally high solar-conversion efficiency achieved with perovskites, their adverse instability remains the key obstacle restricting their wider applications. These ionic crystals can be affected by many factors, such as varied temperatures, humid air, polar solvents, and electron-withdrawing/donating gases. However, under certain controlled conditions, changes in perovskite structures/compositions via, for example, phase transitions, hydration/dehydration, gas adsorption/desorption, and ion intercalation/decalation, can all be reversed, suggesting their great potential for sensing applications. In this contribution, we first overview recent investigations and mechanistic studies on the stability of Metal Halide perovskites under various environmental conditions. Then, we highlight the recent attempts to apply perovskites for the detection of temperature change, humidity, gases, solvents and ions. Finally, we discuss current challenges and future opportunities for developing sensing systems based on Metal Halide perovskites.

Lightmart - One of the best experts on this subject based on the ideXlab platform.

Henry J Snaith - One of the best experts on this subject based on the ideXlab platform.

  • Metal Halide perovskites for energy applications
    Nature Energy, 2016
    Co-Authors: Wei Zhang, Giles E. Eperon, Henry J Snaith
    Abstract:

    Exploring prospective materials for energy production and storage is one of the biggest challenges of this century. Solar energy is one of the most important renewable energy resources, due to its wide availability and low environmental impact. Metal Halide perovskites have emerged as a class of semiconductor materials with unique properties, including tunable bandgap, high absorption coefficient, broad absorption spectrum, high charge carrier mobility and long charge diffusion lengths, which enable a broad range of photovoltaic and optoelectronic applications. Since the first embodiment of perovskite solar cells showing a power conversion efficiency of 3.8%, the device performance has been boosted up to a certified 22.1% within a few years. In this Perspective, we discuss differing forms of perovskite materials produced via various deposition procedures. We focus on their energy-related applications and discuss current challenges and possible solutions, with the aim of stimulating potential new applications.

  • Stability of Metal Halide perovskite solar cells
    Advanced Energy Materials, 2015
    Co-Authors: Tomas Leijtens, Annamaria Petrozza, Nakita K Noel, Severin N Habisreutinger, Giles E. Eperon, Henry J Snaith
    Abstract:

    In recent years, there has been an unprecedented rise in the performance of Metal Halide perovskite solar cells. They are now in a position to compete on performance with traditional crystalline solar cells, and as such the most pressing questions concern the long term operational stability of this class of solar cell. Here, recent developments in understanding and overcoming stability concerns of Metal Halide perovskite solar cells are highlighted. An overview of possible instability issues due to electrical, atmospheric, heat, and light stresses is provided and the different implications to the most commonly used device architectures are discussed.

  • steric engineering of Metal Halide perovskites with tunable optical band gaps
    Nature Communications, 2014
    Co-Authors: Marina R Filip, Giles E. Eperon, Henry J Snaith, Feliciano Giustino
    Abstract:

    The performance of solar cells based on Metal-Halide perovskites has improved rapidly in recent years. First principles calculations and experiments performed by Filip et al. suggest new routes to controlling the band gap of these materials, which could enable further improvements in their performance.

Chenkun Zhou - One of the best experts on this subject based on the ideXlab platform.

  • Multicomponent Organic Metal Halide Hybrid with White Emissions.
    Angewandte Chemie (International ed. in English), 2020
    Co-Authors: Sujin Lee, Haoran Lin, Chenkun Zhou, Xinsong Lin, Logan Ledbetter, Michael Worku, He Liu, Anna Plaviak
    Abstract:

    Zero-dimensional (0D) organic Metal Halide hybrids, in which organic and Metal Halide ions cocrystallize to form neutral species, are a promising platform for the development of multifunctional crystalline materials. Herein we report the design, synthesis, and characterization of a ternary 0D organic Metal Halide hybrid, (HMTA)4 PbMn0.69 Sn0.31 Br8 , in which the organic cation N-benzylhexamethylenetetrammonium (HMTA+ , C13 H19 N4+ ) cocrystallizes with PbBr42- , MnBr42- , and SnBr42- . The wide band gap of the organic cation and distinct optical characteristics of the three Metal bromide anions enabled the single-crystalline "host-guest" system to exhibit emissions from multiple "guest" Metal Halide species simultaneously. The combination of these emissions led to near-perfect white emission with a photoluminescence quantum efficiency of around 73 %. Owing to distinct excitations of the three Metal Halide species, warm- to cool-white emissions could be generated by controlling the excitation wavelength.

  • Hollow Metal Halide Perovskite Nanocrystals with Efficient Blue Emissions
    2019
    Co-Authors: Michael Worku, Haoran Lin, Chenkun Zhou, Yu Tian, Yan Zhou, Maya Chaaban, Drake Beery, Xinsong Lin
    Abstract:

    Metal Halide perovskite nanocrystals (NCs) have emerged as a new generation light emitting materials with narrow emissions and high photoluminescence quantum efficiencies (PLQEs). Various types of perovskite NCs, e.g. platelets, wires, and cubes, have been discovered to exhibit tunable emissions across the whole visible spectral region. Despite remarkable advances in the field of Metal Halide perovskite NCs over the last few years, many nanostructures in inorganic NCs have yet been realized in Metal Halide perovskites and producing highly efficient blue emitting perovskite NCs remains challenging and of great interest. Here we report for the first time the discovery of highly efficient blue emitting cesium lead bromide perovskite (CsPbBr3) NCs with hollow structures. By facile solution processing of cesium lead bromide perovskite precursor solution containing additional ethylenediammonium bromide and sodium bromide, in-situ formation of hollow CsPbBr3 NCs with controlled particle and pore sizes is realized. Synthetic control of hollow nanostructures with quantum confinement effects results in color tuning of CsPbBr3 NCs from green to blue with high PLQEs of up to 81 %.<br><div><br></div>

  • Low dimensional Metal Halide perovskites and hybrids
    Materials Science and Engineering: R: Reports, 2019
    Co-Authors: Chenkun Zhou, Haoran Lin, Sujin Lee, Michael Worku, Maya Chaaban, Xiaoqin Shi
    Abstract:

    Abstract Organic-inorganic Metal Halide hybrids are an important class of crystalline materials with exceptional structural and property tunability. Recently Metal Halide perovskites with ABX3 structure have been extensively investigated as new generation semiconductors for various optoelectronic devices, including photovoltaic cells, light emitting diodes, photodetectors, and lasers, for their exceptional optical and electronic properties. By controlling the morphological dimensionality, low dimensional Metal Halide perovskites, including 2D perovskite nanoplatelets, 1D perovskite nanowires, and 0D perovskite quantum dots, have been developed to exhibit distinct properties from their bulk counterparts, due to quantum size effects. Besides ABX3 perovskites, organic-inorganic Metal Halide hybrids, containing the same fundamental building block of Metal Halide octahedra (BX6), can also be assembled to possess other types of crystallographic structures. Using appropriate organic and inorganic components, low dimensional organic-inorganic Metal Halide hybrids with 2D, quasi-2D, corrugated-2D, 1D, and 0D structures at the molecular level have been developed and studied. Due to the strong quantum confinement and site isolation, these low dimensional Metal Halide hybrids at the molecular level exhibit remarkable and unique properties that are significantly different from those of ABX3 perovskites. In light of the rapid development of low dimensional Metal Halide perovskites and hybrids, it is indeed timely to review the recent progress in these areas. Also, there is a need to clarify the difference between morphological low dimensional Metal Halide perovskites and molecular level low dimensional Metal Halide hybrids, as currently the terminologies of low dimensional perovskites are not appropriately used in many cases. In this review article, we discuss the synthesis, characterization, application, and computational studies of low dimensional Metal Halide perovskites and hybrids.

  • Blue Emitting Single Crystalline Assembly of Metal Halide Clusters
    Journal of the American Chemical Society, 2018
    Co-Authors: Chenkun Zhou, Haoran Lin, Yu Tian, Jennifer Neu, Yan Zhou, Sujin Lee, Michael Worku, Peter I. Djurovich, Theo Siegrist
    Abstract:

    The rich chemistry of organic–inorganic Metal Halide hybrids has enabled the development of a variety of crystalline structures with controlled morphological and molecular dimensionalities. Here we report for the first time a single crystalline assembly of Metal Halide clusters, (C9NH20)7(PbCl4)Pb3Cl11, in which lead chloride tetrahedrons (PbCl42–) and face-sharing lead chloride trimer clusters (Pb3Cl115–) cocrystallize with organic cations (C9NH20+) to form a periodical zero-dimensional (0D) structure at the molecular level. Blue light emission peaked at 470 nm with a photoluminescence quantum efficiency (PLQE) of around 83% was realized for this single crystalline hybrid material, which is attributed to the individual lead chloride clusters. Our discovery of single crystalline assembly of Metal Halide clusters paves a new path to functional cluster assemblies with highly tunable structures and remarkable properties.

  • Luminescent zero-dimensional organic Metal Halide hybrids with near-unity quantum efficiency
    Chemical science, 2017
    Co-Authors: Chenkun Zhou, Haoran Lin, Yu Tian, Yan Zhou, Zhao Yuan, Ronald A. Clark, Banghao Chen, Lambertus J. Van De Burgt, Jamie C. Wang, Kenneth Hanson
    Abstract:

    Single crystalline zero-dimensional (0D) organic-inorganic hybrid materials with perfect host-guest structures have been developed as a new generation of highly efficient light emitters. Here we report a series of lead-free organic Metal Halide hybrids with a 0D structure, (C4N2H14X)4SnX6 (X = Br, I) and (C9NH20)2SbX5 (X = Cl), in which the individual Metal Halide octahedra (SnX64-) and quadrangular pyramids (SbX52-) are completely isolated from each other and surrounded by the organic ligands C4N2H14X+ and C9NH20+, respectively. The isolation of the photoactive Metal Halide species by the wide band gap organic ligands leads to no interaction or electronic band formation between the Metal Halide species, allowing the bulk materials to exhibit the intrinsic properties of the individual Metal Halide species. These 0D organic Metal Halide hybrids can also be considered as perfect host-guest systems, with the Metal Halide species periodically doped in the wide band gap matrix. Highly luminescent, strongly Stokes shifted broadband emissions with photoluminescence quantum efficiencies (PLQEs) of close to unity were realized, as a result of excited state structural reorganization of the individual Metal Halide species. Our discovery of highly luminescent single crystalline 0D organic-inorganic hybrid materials as perfect host-guest systems opens up a new paradigm in functional materials design.

Haoran Lin - One of the best experts on this subject based on the ideXlab platform.

  • Multicomponent Organic Metal Halide Hybrid with White Emissions.
    Angewandte Chemie (International ed. in English), 2020
    Co-Authors: Sujin Lee, Haoran Lin, Chenkun Zhou, Xinsong Lin, Logan Ledbetter, Michael Worku, He Liu, Anna Plaviak
    Abstract:

    Zero-dimensional (0D) organic Metal Halide hybrids, in which organic and Metal Halide ions cocrystallize to form neutral species, are a promising platform for the development of multifunctional crystalline materials. Herein we report the design, synthesis, and characterization of a ternary 0D organic Metal Halide hybrid, (HMTA)4 PbMn0.69 Sn0.31 Br8 , in which the organic cation N-benzylhexamethylenetetrammonium (HMTA+ , C13 H19 N4+ ) cocrystallizes with PbBr42- , MnBr42- , and SnBr42- . The wide band gap of the organic cation and distinct optical characteristics of the three Metal bromide anions enabled the single-crystalline "host-guest" system to exhibit emissions from multiple "guest" Metal Halide species simultaneously. The combination of these emissions led to near-perfect white emission with a photoluminescence quantum efficiency of around 73 %. Owing to distinct excitations of the three Metal Halide species, warm- to cool-white emissions could be generated by controlling the excitation wavelength.

  • Hollow Metal Halide Perovskite Nanocrystals with Efficient Blue Emissions
    2019
    Co-Authors: Michael Worku, Haoran Lin, Chenkun Zhou, Yu Tian, Yan Zhou, Maya Chaaban, Drake Beery, Xinsong Lin
    Abstract:

    Metal Halide perovskite nanocrystals (NCs) have emerged as a new generation light emitting materials with narrow emissions and high photoluminescence quantum efficiencies (PLQEs). Various types of perovskite NCs, e.g. platelets, wires, and cubes, have been discovered to exhibit tunable emissions across the whole visible spectral region. Despite remarkable advances in the field of Metal Halide perovskite NCs over the last few years, many nanostructures in inorganic NCs have yet been realized in Metal Halide perovskites and producing highly efficient blue emitting perovskite NCs remains challenging and of great interest. Here we report for the first time the discovery of highly efficient blue emitting cesium lead bromide perovskite (CsPbBr3) NCs with hollow structures. By facile solution processing of cesium lead bromide perovskite precursor solution containing additional ethylenediammonium bromide and sodium bromide, in-situ formation of hollow CsPbBr3 NCs with controlled particle and pore sizes is realized. Synthetic control of hollow nanostructures with quantum confinement effects results in color tuning of CsPbBr3 NCs from green to blue with high PLQEs of up to 81 %.<br><div><br></div>

  • Low dimensional Metal Halide perovskites and hybrids
    Materials Science and Engineering: R: Reports, 2019
    Co-Authors: Chenkun Zhou, Haoran Lin, Sujin Lee, Michael Worku, Maya Chaaban, Xiaoqin Shi
    Abstract:

    Abstract Organic-inorganic Metal Halide hybrids are an important class of crystalline materials with exceptional structural and property tunability. Recently Metal Halide perovskites with ABX3 structure have been extensively investigated as new generation semiconductors for various optoelectronic devices, including photovoltaic cells, light emitting diodes, photodetectors, and lasers, for their exceptional optical and electronic properties. By controlling the morphological dimensionality, low dimensional Metal Halide perovskites, including 2D perovskite nanoplatelets, 1D perovskite nanowires, and 0D perovskite quantum dots, have been developed to exhibit distinct properties from their bulk counterparts, due to quantum size effects. Besides ABX3 perovskites, organic-inorganic Metal Halide hybrids, containing the same fundamental building block of Metal Halide octahedra (BX6), can also be assembled to possess other types of crystallographic structures. Using appropriate organic and inorganic components, low dimensional organic-inorganic Metal Halide hybrids with 2D, quasi-2D, corrugated-2D, 1D, and 0D structures at the molecular level have been developed and studied. Due to the strong quantum confinement and site isolation, these low dimensional Metal Halide hybrids at the molecular level exhibit remarkable and unique properties that are significantly different from those of ABX3 perovskites. In light of the rapid development of low dimensional Metal Halide perovskites and hybrids, it is indeed timely to review the recent progress in these areas. Also, there is a need to clarify the difference between morphological low dimensional Metal Halide perovskites and molecular level low dimensional Metal Halide hybrids, as currently the terminologies of low dimensional perovskites are not appropriately used in many cases. In this review article, we discuss the synthesis, characterization, application, and computational studies of low dimensional Metal Halide perovskites and hybrids.

  • Blue Emitting Single Crystalline Assembly of Metal Halide Clusters
    Journal of the American Chemical Society, 2018
    Co-Authors: Chenkun Zhou, Haoran Lin, Yu Tian, Jennifer Neu, Yan Zhou, Sujin Lee, Michael Worku, Peter I. Djurovich, Theo Siegrist
    Abstract:

    The rich chemistry of organic–inorganic Metal Halide hybrids has enabled the development of a variety of crystalline structures with controlled morphological and molecular dimensionalities. Here we report for the first time a single crystalline assembly of Metal Halide clusters, (C9NH20)7(PbCl4)Pb3Cl11, in which lead chloride tetrahedrons (PbCl42–) and face-sharing lead chloride trimer clusters (Pb3Cl115–) cocrystallize with organic cations (C9NH20+) to form a periodical zero-dimensional (0D) structure at the molecular level. Blue light emission peaked at 470 nm with a photoluminescence quantum efficiency (PLQE) of around 83% was realized for this single crystalline hybrid material, which is attributed to the individual lead chloride clusters. Our discovery of single crystalline assembly of Metal Halide clusters paves a new path to functional cluster assemblies with highly tunable structures and remarkable properties.

  • Luminescent zero-dimensional organic Metal Halide hybrids with near-unity quantum efficiency
    Chemical science, 2017
    Co-Authors: Chenkun Zhou, Haoran Lin, Yu Tian, Yan Zhou, Zhao Yuan, Ronald A. Clark, Banghao Chen, Lambertus J. Van De Burgt, Jamie C. Wang, Kenneth Hanson
    Abstract:

    Single crystalline zero-dimensional (0D) organic-inorganic hybrid materials with perfect host-guest structures have been developed as a new generation of highly efficient light emitters. Here we report a series of lead-free organic Metal Halide hybrids with a 0D structure, (C4N2H14X)4SnX6 (X = Br, I) and (C9NH20)2SbX5 (X = Cl), in which the individual Metal Halide octahedra (SnX64-) and quadrangular pyramids (SbX52-) are completely isolated from each other and surrounded by the organic ligands C4N2H14X+ and C9NH20+, respectively. The isolation of the photoactive Metal Halide species by the wide band gap organic ligands leads to no interaction or electronic band formation between the Metal Halide species, allowing the bulk materials to exhibit the intrinsic properties of the individual Metal Halide species. These 0D organic Metal Halide hybrids can also be considered as perfect host-guest systems, with the Metal Halide species periodically doped in the wide band gap matrix. Highly luminescent, strongly Stokes shifted broadband emissions with photoluminescence quantum efficiencies (PLQEs) of close to unity were realized, as a result of excited state structural reorganization of the individual Metal Halide species. Our discovery of highly luminescent single crystalline 0D organic-inorganic hybrid materials as perfect host-guest systems opens up a new paradigm in functional materials design.