The promise of graphene and its derivatives as next generation sensors for real-time detection of toxic heavy metals (HM) requires a clear understanding of behavior of these metals on the graphene surface and response of the graphene to adsorption events. Our calculations herein were focused on the investigation of the interaction between three HMs, namely Cd, Hg and Pb, with graphene quantum dots (GQDs). We determine binding energies and heights of both neutral and charged HM ions on these GQDs. The results show that the adsorption energy of donor-like physisorbed neutral Pb atoms is larger than that of either Cd or Hg. In contrast to the donor-like behavior of elemental HMs, the chemisorbed charged HM species act as typical acceptors. The energy barriers to migration of the neutral adatoms on GQDs are also estimated. In addition, we show how the substitution of a carbon atom by a HM adatom changes the geometric structure of GQDs and hence their electronic and vibrational properties. UV-visible absorption spectra of HM-adsorbed GQDs vary with the size and shape of the GQD. Based on our results, we suggest a route towards the development of a graphene-based sensing platform for the optical detection of toxic HMs. ; Funding Agencies|European Union [696656]; Swedish Research Council (VR) [621-2014-5805]; Angpanneforeningens Forskningsstiftelse [16-541]; Science Foundation Ireland (SFI) under its Starter Investigator Research Grant (SIRG) Programme [15/SIRG/3314]; Swedish Research Council (VR) Marie Sklodowska Curie International Career Grant [2015-00679]; AForsk [14-517]; Swedish Government Strategic Research Areas in Materials Science on Functional Materials at Linkoping University [2009-00971]; Knut and Alice Wallenberg Foundation through the Strong Field Physics and New States of Matter Grant; Ministry of Education and Science of the Russian Federation [14.Y26.31.0005]
We report a systematic study of the efficiency limitations of non-fullerene organic solar cells that exhibit a small energy loss (E-loss) between the polymer donor and the non-fullerene acceptor. To clarify the impact of Eloss on the performance of the solar cells, three thieno[3,4-c] pyrrole-4,6-dione-based conjugated polymers (PTPD3T, PTPD2T, and PTPDBDT) are employed as the electron donor, which all have complementary absorption spectra compared with the ITIC acceptor. The corresponding photovoltaic devices show that low Eloss (0.54 eV) in PTPDBDT: ITIC leads to a high open-circuit voltage (Voc) of 1.05 V, but also to a small quantum efficiency, and in turn photocurrent. The high Voc or small energy loss in the PTPDBDT-based solar cells is a consequence of less non-radiative recombination, whereas the low quantum efficiency is attributed to the unfavorable micro-phase separation, as confirmed by the steady-state and time-resolved photoluminescence experiments, grazing-incidence wide-angle X-ray scattering, and resonant soft X-ray scattering (R-SoXS) measurements. We conclude that to achieve high performance non-fullerene solar cells, it is essential to realize a large Voc with small Eloss while simultaneously maintaining a high quantum efficiency by manipulating the molecular interaction in the bulk-heterojunction. ; Funding Agencies|Ministry of science and technology [2016YFA0200700]; Recruitment Program of Global Youth Experts of China; National Natural Science Foundation of China [21574138, 91233205, 91633301]; Strategic Priority Research Program of the Chinese Academy of Sciences [XDB12030200]; Swedish Research Council [VR621-2013-5561]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [200900971]; Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy [DE-AC02-05CH11231]; Alexander-von-Humboldt foundation; King Abdullah University of Science and Technology (KAUST)
Theoretical modelling predicts very unusual structures and properties of materials at extreme pressure and temperature conditions(1,2). Hitherto, their synthesis and investigation above 200 gigapascals have been hindered both by the technical complexity of ultrahigh-pressure experiments and by the absence of relevant in situ methods of materials analysis. Here we report on a methodology developed to enable experiments at static compression in the terapascal regime with laser heating. We apply this method to realize pressures of about 600 and 900 gigapascals in a laser-heated double-stage diamond anvil cell(3), producing a rhenium-nitrogen alloy and achieving the synthesis of rhenium nitride Re7N3-which, as our theoretical analysis shows, is only stable under extreme compression. Full chemical and structural characterization of the materials, realized using synchrotron single-crystal X-ray diffraction on microcrystals in situ, demonstrates the capabilities of the methodology to extend high-pressure crystallography to the terapascal regime. ; Funding Agencies: Alexander von Humboldt Foundation; Deutsche Forschungsgemeinschaft (DFG) [LA-4916/1-1, BY112/2-1, DU 954-11/1, DU 393-9/2, DU 393-13/2]; Federal Ministry of Education and Research, Germany (BMBF) [05K19WC1]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linköping University (Faculty Grant SFO-Mat-LiU) [200900971]; National Science Foundation -Earth Sciences [EAR -1634415]; DOE Office of Science [DE-AC02-06CH11357]; Russian Science Foundation [18-12-00492]; Knut and Alice Wallenberg Foundation (Wallenberg Scholar grant) [KAW-2018.0194]; Swedish Government Strategic Research Areas in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]; Swedish e-science Research Center (SeRC); Swedish Research Council (VR) [2019-05600]; Swedish Foundation for Strategic Research (SSF) [EM160004]; Swedish Research Council [2016-07213]; VINN Excellence Center Functional Nanoscale ...
Bright and efficient blue emission is key to further development of metal halide perovskite light-emitting diodes. Although modifying bromide/chloride composition is straightforward to achieve blue emission, practical implementation of this strategy has been challenging due to poor colour stability and severe photoluminescence quenching. Both detrimental effects become increasingly prominent in perovskites with the high chloride content needed to produce blue emission. Here, we solve these critical challenges in mixed halide perovskites and demonstrate spectrally stable blue perovskite light-emitting diodes over a wide range of emission wavelengths from 490 to 451 nanometres. The emission colour is directly tuned by modifying the halide composition. Particularly, our blue and deep-blue light-emitting diodes based on three-dimensional perovskites show high EQE values of 11.0% and 5.5% with emission peaks at 477 and 467nm, respectively. These achievements are enabled by a vapour-assisted crystallization technique, which largely mitigates local compositional heterogeneity and ion migration. Achieving bright and efficient blue emission in metal halide perovskite light-emitting diodes has proven to be challenging. Here, the authors demonstrate high EQE and spectrally stable blue light-emitting diodes based on mixed halide perovskites, with emission from 490 to 451nm by using a vapour-assisted crystallization technique. ; Funding Agencies|ERC Starting GrantEuropean Research Council (ERC) [717026]; Swedish Energy Agency EnergimyndighetenSwedish Energy Agency [48758-1, 44651-1]; Swedish Research Council VRSwedish Research Council; NanoLund; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; Bundesministerium fur Bildung und Forschung (BMBF Hyper project)Federal Ministry of Education & Research (BMBF) [03SF0514C]; DFG within the framework of SPP 2196 programmeGerman Research Foundation (DFG) [DE 830/22-1]; National Key Research and Development Program of China [2016YFB0700700]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [11704015, 51621003, 12074016]; Scientific Research Key Program of Beijing Municipal Commission of Education, China [KZ201310005002]; Beijing Innovation Team Building Program, China [IDHT20190503]
Strong light-matter coupling can form hybrid states at new energy levels that share properties of both light and matter. This principle offers new routes to control material functions without modifying the chemical structure of molecules. In this work, we coupled ambipolar semiconducting thin films to a Fabry-Perot cavity and investigated effects on charge transport. By constructing thin-film transistors inside optical cavities, we could simultaneously study coupling features and charge transport in the same samples. The cavity resonance was detuned by controlling the thickness of the top spacer layer in the cavity. We found no significant influence on charge transport for our systems, which may be related to insufficiently strong coupling. Possible additional origins and future directions are also discussed. ; Funding Agencies|Wenner-Gren Foundations; Swedish Research CouncilSwedish Research CouncilEuropean Commission [621-2014-5599]; Swedish Foundation for Strategic ResearchSwedish Foundation for Strategic Research; AForsk foundation; National Research Foundation of Korea (NRF)National Research Foundation of Korea; Korea government (MSIT)Korean Government [2020R1A2C1102558]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]
Metal halide perovskites have shown rapid development in various fields such as photovoltaics, photodetectors, light-emitting diodes (LEDs), and optically pumped lasers owing to their superior optoelectronic properties. Here, we review the basic optoelectronic properties of halide perovskites from a photophysical perspective. We highlight that halide perovskites are promising in various optoelectronic devices functioning at a wide range of carrier densities. We discuss optically and electrically generated carrier density under two different excitation modes [continuous wave (CW) and pulsed] as well as the impact of carrier density on the optoelectronic behavior of perovskites. Moreover, we discuss lasing actions at high carrier densities and summarize key rules to evaluate the lasing actions. Last, we provide an outlook on perovskite-based electrically pumped lasers. ; Funding Agencies|ERC Starting GrantEuropean Research Council (ERC) [717026]; Swedish Energy Agency EnergimyndighetenSwedish Energy Agency [48758-1, 44651-1]; Swedish Foundation for International Cooperation in Research and Higher Education [CH2018-7736]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]
Engineering a low singlet-triplet energy gap (Delta E-ST) is necessary for efficient reverse intersystem crossing (rISC) in delayed fluorescence (DF) organic semiconductors but results in a small radiative rate that limits performance in LEDs. Here, we study a model DF material, BF2, that exhibits a strong optical absorption (absorption coefficient = 3.8 x 10(5) cm(-1)) and a relatively large Delta E-ST of 0.2 eV. In isolated BF2 molecules, intramolecular rISC is slow (delayed lifetime = 260 mu s), but in aggregated films, BF2 generates intermolecular charge transfer (inter-CT) states on picosecond timescales. In contrast to the microsecond intramolecular rISC that is promoted by spin-orbit interactions in most isolated DF molecules, photoluminescence-detected magnetic resonance shows that these inter-CT states undergo rISC mediated by hyperfine interactions on a similar to 24 ns timescale and have an average electron-hole separation of >= 1.5 nm. Transfer back to the emissive singlet exciton then enables efficient DF and LED operation. Thus, access to these inter-CT states, which is possible even at low BF2 doping concentrations of 4 wt%, resolves the conflicting requirements of fast radiative emission and low Delta E-ST in organic DF emitters. ; Funding Agencies|Simons Foundation [601946]; EPSRCUK Research & Innovation (UKRI)Engineering & Physical Sciences Research Council (EPSRC) [EP/M01083X/1, EP/M005143/1, EP/L01551X/1]; European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programmeEuropean Research Council (ERC) [670405]; Swedish Energy AgencySwedish Energy AgencyMaterials & Energy Research Center (MERC) [EM-48594-1]; Swedish Research CouncilSwedish Research CouncilEuropean Commission [VR-2017-05285]; Aix Marseille Universite; CNRSCentre National de la Recherche Scientifique (CNRS)European Commission; Basque GovernmentBasque Government [PIBA19-0004]; Spanish Government MINECO/FEDERSpanish Government [PID2019-109555GB-I00]; European Unions Horizon 2020 research and innovation programme under Marie Skodowska Curie Grant [722651]; Fonds de la Recherche Scientifiques de Belgique (F.R.S.-FNRS)Fonds de la Recherche Scientifique - FNRS [2.5020.11]; Tier-1 supercomputer of the Federation Wallonie-Bruxelles; Walloon Region [1117545]; FRS-FNRSFonds de la Recherche Scientifique - FNRS [F.4534.21]; Fonds pour la formation a la Recherche dans lIndustrie et dans lAgriculture (F.R.I.A.) of the F.R.S.-F.N.R.S
Approximately 90% of cancers originate in epithelial tissues leading to epithelial thickening, but the ultrastructural changes and underlying architecture are less well known. Depth resolved label free visualization of nanoscale tissue morphology is required to reveal the extent and distribution of ultrastructural changes in underlying tissue, but is difficult to achieve with existing imaging modalities. We developed a nanosensitive optical coherence tomography (nsOCT) approach to provide suchimaging based on dominant axial structure with a few nanometre detection accuracy. nsOCT maps the distribution of axial structural sizes an order of magnitude smaller than the axial resolution of the system. We validated nsOCT methodology by detecting synthetic axial structure via numerical simulations. Subsequently, we validated the nsOCT technique experimentally by detecting known structures from a commercially fabricated sample. nsOCT reveals scaling with different depth of dominant submicronstructural changes associated with carcinoma which may inform the origins of the disease, its progression and improve diagnosis. ; Funding agencies: Irish Research Council(IRC), under Government of Ireland postdoctoral fellowship with project ID: GOIPD/2017/837; European Union's Horizon 2020 research and innovationprogram under grant agreements no. 761214 and no. 779960; NUI Galway, Galway University Foundation; the University of Limerick Foundation; the National Biophotonics Imaging Platform (NBIP) Ireland funded under the Higher Education Authority PRTLI Cycle 4 and cofunded by the Irish Government and the European Union.
In the ongoing sensor-camouflage duel, new functionalities and sensing abilities are continuously incorporated in detector devices, requiring new capabilities on the camouflage side. The aim of this work is to contribute to improved camouflage including low polarization detectability in wavelength regions with both visible and invisible light. To find new surfaces that can be used as camouflage, we seek for materials that in a spectral design perspective meet the requests of military utility. We have represented this with a 'ladder model' which step by step connects the system and requirements aspects from a basic material level to a useful application. The focus in this study is mainly on the first rungs of the 'ladder' which are addressing aspects of spectral design and systems engineering as well as requirements of camouflage materials. We have stated six criteria for evaluating camouflage materials and their interactions with light. The criteria are related to reflection, gloss, degree of polarization, emissivity, broadband and dynamic properties. The included papers can be divided into two parts. The first part is related to aspects of the evaluation criteria for camouflage and the second part presents studies of bio-inspired materials and their performance related to the evaluation criteria. In connection with the presentation of the 'ladder model' for military utility and the six criteria for camouflage, several materials divided into the four categories: pigments, thin film coatings, multidimensional structures and metamaterials are surveyed. We also studied higher system design levels evaluating the visual and thermal contrast by inspecting images of an object's surface in a background. Important terms and parameters at this level were detectability and the lightness of a color. Furthermore a literature review of polarimetric environmental background properties was performed together with a reference materials study. Camouflage properties of several organic material surfaces have been studied. The biopolymeric materials range from beetle cuticle to cellulose based foams and protein fibres. In addition to white structures, we also investigated dynamic properties and initiated work using organic dyes to expand the use of the studied materials to camouflage applications. The main characterization techniques were reflection spectrometry, scatterometry and Mueller-matrix ellipsometry. These methods were used with an aim to mainly investigate the first three camouflage criteria (reflection, gloss, degree of polarization) but also touching on emissivity and dynamic coloring. Overall, the academic approach have been balanced with the requests and limits given by the military utility. The results will contribute to better camouflage by using advanced bio-inspired materials. ; I den pågående duellen mellan sensorer och kamouflage, inkluderas nya funktioner i sensorenheterna, vilket kräver nya funktioner också på kamouflagesidan. Syftet med detta arbete är att bidra till förbättrat kamouflage. Detta inkluderar låg polariseringsgrad för lägre detekterbarhet både i våglängdsområden för synligt och osynligt ljus. För att hitta nya ytor som kan fungera som kamouflage söker vi material som i ett spektralt designperspektiv uppfyller krav på militär nytta. Vi har representerat detta med en 'stegmodell'. Fokus i denna studie ligger främst på 'stegens' första pinnar som tar upp aspekter av spektral design och systemteknik. Vi har angett sex kriterier för att värdera kamouflagematerial och deras interaktion med ljus. Kriterierna är relaterade till reflektion, glans, polarisationsgrad, emissivitet, bredbandighet och dynamiska egenskaper. De inkluderade artiklarna kan delas in i två delar. De tre första relaterar till aspekter av kamouflagevärderingskriterier och de tre följande till studier av bioinspirerade material och deras prestanda utifrån värderingskriterierna. 'Stegmodellen' presenteras som ett verktyg för att åstadkomma och bedöma militär nytta vid systemdesign och systemutveckling samt för kravställning. I samma sammanhang introduceras de sex kriterierna för kamouflage och en litteraturstudie görs om material indelade i de fyra kategorierna pigment, tunnfilmsbeläggningar, flerdimensionella strukturer och metamaterial. Vi studerar också högre systemdesignnivåer för att utvärdera den visuella och termiska kontrasten genom att inspektera bilder av en objektyta i en bakgrund. Viktiga termer och parametrar på denna nivå är detekterbarhet och ljushet i färg. Dessutom görs en litteraturgenomgång av polarimetrisk omgivande bakgrund, tillsammans med en kamouflagestudie av referensmaterial. Kamouflageegenskaper hos flera ytor studeras. Materialen är bioinspirerade och sträcker sig från skalbaggevingar till cellulosabaserade skum och protein_brer. Förutom vita strukturer har vi även undersökt dynamiska egenskaper samt initierat arbeten med organiska färgämnen för att kunna utöka användningen av våra material till fler kamouflagetillämpningar. De viktigaste karakteriseringsteknikerna som användes var reflektionsspektrometri, skatterometri och Mueller-matris-ellipsometri, huvudsakligen i syfte att undersöka de tre första kamouflagekriterierna reflektion, glans och polarisationsgrad. Också emissivitet och dynamiska egenskaper berörs. Sammantaget har det akademiska tillvägagångssättet balanserats med önskemål och begränsningar som följer av den militära tillämpningen och krav på nytta. Resultaten kommer förhoppningsvis att bidra till bättre kamouflage genom att använda avancerade bioinspirerade material.
Materials that provide independent control of infrared thermal radiation and haze in the visible could benefit many areas and applications, including clothing, packaging and photovoltaics. Here, we study this possibility for a metamaterial composite paper based on cellulose nanofibrils (CNF) and silicon dioxide (SiO2) microparticles with infrared (IR) Frohlich phonon resonances. This CNF-SiO2 composite shows outstanding transparency in the visible wavelength range, with the option of controlling light diffusion and haze from almost zero to 90% by varying the SiO2 microparticle concentration. We further show that the transparent metamaterial paper could maintain high thermal emissivity in the atmospheric IR window, as attributed to strong IR absorption of both the nanocellulose and the resonant SiO2 microparticles. The high IR emissivity and low visible absorption make the paper suitable for passive radiative cooling and we demonstrate cooling of the paper to around 3 degrees C below ambient air temperature by exposing it to the sky. ; Funding Agencies|Knut and Allice Wallenberg Foundation via a Wallenberg Scholarship; Knut and Alice Wallenberg foundationKnut & Alice Wallenberg Foundation; Linkoping University; Wallenberg Wood Science Center; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]; Swedish Foundation for Strategic ResearchSwedish Foundation for Strategic Research; Swedish Armed Forces Research and Technology programme
Several beetle species in the Scarabaeoidea superfamily reflect left-handed polarized light due to a circular Bragg structure in their cuticle. The right-handed polarized light is transmitted. The objective here is to evaluate cuticle chiral properties in an effective medium approach using transmission Mueller matrices assuming the cuticle to be a bianisotropic continuum. Both differential decomposition and nonlinear regression were used in the spectral range of 500-1690nm. The former method provides the sample cumulated birefringence and dichroic optical properties and is model-free but requires a homogeneous sample. The materials chirality is deduced from the circular birefringence and circular dichroic spectra obtained. The regression method requires dispersion models for the optical functions but can also be used in more complex structures including multilayered and graded media. It delivers the material properties in terms of model functions of materials permittivity and chirality. The two methods show excellent agreement for the complex-valued chirality spectrum of the cuticle. ; Funding Agencies|Knut and Alice Wallenberg FoundationKnut & Alice Wallenberg Foundation; Swedish Government Strategic Research Area in Materials Science on Advanced Functional Materials at Linkoping University [SFO-Mat-LiU, 2009-00971]
Spintronics holds great potential for next-generation high-speed and low-power consumption information technology. Recently, lead halide perovskites (LHPs), which have gained great success in optoelectronics, also show interesting magnetic properties. However, the spin-related properties in LHPs originate from the spin-orbit coupling of Pb, limiting further development of these materials in spintronics. Here, we demonstrate a new generation of halide perovskites, by alloying magnetic elements into optoelectronic double perovskites, which provide rich chemical and structural diversities to host different magnetic elements. In our iron-alloyed double perovskite, Cs2Ag(Bi:Fe)Br-6, Fe3+ replaces Bi3+ and forms FeBr6 clusters that homogenously distribute throughout the double perovskite crystals. We observe a strong temperature-dependent magnetic response at temperatures below 30 K, which is tentatively attributed to a weak ferromagnetic or antiferromagnetic response from localized regions. We anticipate that this work will stimulate future efforts in exploring this simple yet efficient approach to develop new spintronic materials based on lead-free double perovskites. ; Funding Agencies|Knut and Alice Wallenberg FoundationKnut & Alice Wallenberg Foundation [KAW 2019.0082]; Swedish Energy AgencySwedish Energy Agency [2018004357, P43288-1]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009-00971]; Grant Agency of the Czech RepublicGrant Agency of the Czech Republic [GA19-05259S]; China Scholarship Council (CSC)China Scholarship Council; U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering DivisionUnited States Department of Energy (DOE); European CommunityEuropean Community (EC) [312284]; Czech Ministry of EducationMinistry of Education, Youth & Sports - Czech Republic [LM2015057]; CERIC users grant; International Synchrotron Access Program of the Australian Synchrotron
Electrically conducting polymers (ECPs) are becoming increasingly important in areas such as optoelectronics, biomedical devices, and energy systems. Still, their detailed charge transport properties produce an anomalous optical conductivity dispersion that is not yet fully understood in terms of physical model equations for the broad range optical response. Several modifications to the classical Drude model have been proposed to account for a strong non-Drude behavior from terahertz (THz) to infrared (IR) ranges, typically by implementing negative amplitude oscillator functions to the model dielectric function that effectively reduce the conductivity in those ranges. Here we present an alternative description that modifies the Drude model via addition of positive-amplitude Lorentz oscillator functions. We evaluate this so-called Drude-Lorentz (DL) model based on the first ultra-wide spectral range ellipsometry study of ECPs, spanning over four orders of magnitude: from 0.41 meV in the THz range to 5.90 eV in the ultraviolet range, using thin films of poly(3,4-ethylenedioxythiophene): tosylate (PEDOT: Tos) as a model system. The model could accurately fit the experimental data in the whole ultrawide spectral range and provide the complex anisotropic optical conductivity of the material. Examining the resonance frequencies and widths of the Lorentz oscillators reveals that both spectrally narrow vibrational resonances and broader resonances due to localization processes contribute significantly to the deviation from the Drude optical conductivity dispersion. As verified by independent electrical measurements, the DL model accurately determines the electrical properties of the thin film, including DC conductivity, charge density, and (anisotropic) mobility. The ellipsometric method combined with the DL model may thereby become an effective and reliable tool in determining both optical and electrical properties of ECPs, indicating its future potential as a contact-free alternative to traditional electrical characterization. ; Funding Agencies|Swedish Research Council; Swedish Foundation for Strategic Research; Wenner-Gren Foundations; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]
Conjugated polymer-polyelectrolyte blends combine and couple electronic semiconductor functionality with selective ionic transport, making them attractive as the active material in organic biosensors and bioelectronics, electrochromic displays, neuromorphic computing, and energy conversion and storage. Although extensively studied and explored, fundamental knowledge and accurate quantitative models of the coupled ion-electron functionality and transport are still lacking to predict the characteristics of electrodes and devices based on these blends. We report on a two-phase model, which couples the chemical potential of the holes, in the conjugated polymer, with the electric double layer residing at the conjugated polymer-polyelectrolyte interface. The model reproduces a wide range of experimental charging and transport data and provides a coherent theoretical framework for the system as well as local electrostatic potentials, energy levels, and charge carrier concentrations. This knowledge is crucial for future developments and optimizations of bioelectronic and energy devices based on the electronic-ionic interaction within these materials. ; Funding Agencies|Swedish Research Council [637-2013-7301, 2016-05990]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]; Swedish Energy Agency [38332-1]; Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University; Onnesjo Foundation; Swedish Foundation for Strategic Research; Knut and Alice Wallenberg Foundation
The preparation of highly efficient perovskite nanocrystal light-emitting diodes is shown. A new trimethylaluminum vapor-based crosslinking method to render the nanocrystal films insoluble is applied. The resulting near-complete nanocrystal film coverage, coupled with the natural confinement of injected charges within the perovskite crystals, facilitates electron-hole capture and give rise to a remarkable electroluminescence yield of 5.7%. ; Funding Agencies|EPSRC [EP/M005143/1, EP/J017361/1, EP/G037221/1]; Gates Cambridge Trust; CNPq [246050/2012-8]; ERC [259619 PHOTO-EM]; EU [312483 ESTEEM2]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [200900971]; Cambridge Commonwealth European and International Trust; Cambridge Australian Scholarships