Componentwise eigenvalue condition numbers for different representations of tridiagonal and banded matrices

Sensitivity analysis is a tool for the validation of the quality of computed eigenvalues, having wide ranges of applications in natural and applied science. For modelling strenght, elasticity, de- formations, PID controller ( Proportional-Integral-Derivative controller) and many other prob- lems, there is a need for computing reliably eigenvalues. Componentwise relative perturbation analysis can provide good estimations of the accuracy of these eigenvalues. In this undergrad- uate thesis project we provide an expression for the 2-norm of an special vector.El an alisis de sensibilidad es una herramienta para la validaci on de la calidad de los au- tovalores computados. Tiene amplios rangos de aplicaci on en ciencias naturales y aplicadas. Para modelar fuerzas, elasticidad, deformaciones, controladores PDI (Proportional-Integral- Derivative controller) y otros muchos par ametros, hay una necesidad de con abilidad en el c omputo de autovalores. El an alisis de perturbaci on por componentes relativo puede proveer buenas estimaciones de la precisi on de esos autovalores.Ingeniería en Tecnologías Industriale

El prefecto del pretorio: una figura dominante de la política romana en el siglo III

El artículo analiza el desarrollo de la figura del Prefecto del Pretorio, que desde sus comienzos fue una de las más importantes dentro de las instituciones de estado romanas, pero que con la llegada de los cambios políticos después de la muerte de Marco Aurelio, aumentó su protagonismo hasta el punto de gozar de más poder en ocasiones que el mismo emperador. La coyuntura inestable y las fuertes prerrogativas de las que gozaba convirtieron a ese alto funcionario, mitad militar y mitad burócrata, en un personaje clave dentro de las intrigas políticas romanas, que desde su posición inigualable fue capaz a menudo de eliminar al emperador mediante una conspiración para ocupar su lugar. La situación se hizo tan grave llegado el siglo IV que Constantino decidió retirarle el mando de tropas y las funciones militares, convirtiendo al Prefecto del Pretorio en un juez supremo y organizador del suministro.«The Praetorian Prefect: a Commanding Figure of the Roman Politics in the Third Century (199-284)» analyzes the developing of the Praetorian Prefect character, who was from the beginning one of the most important in the roman state institutions, but with the arrival of the political changes after the death of Marcus Aurelius, enhanced his leading role to the point of sometimes exceeding the power of the emperor himself. The instable circumstances and his strong prerogatives turned that high functionary, half bureaucrat half military, into a key figure inside the roman political intrigues, and from his position he was quite often able to eliminate the emperor with a conspiracy, and then take his place. The situation was so serious with the rising of the Fourth Century that the emperor Constantine decided to remove the military functions and the troop leading of the Praetorian Prefects, making them supreme judges and high offi cials of supply organization

Dietrich I von Mörs (1226-1262). Paradigmatic example of the new medieval german nobility after the era of Innocent III

Uno de los aspectos más importantes de la política exterior del papa Inocencio III fue su relación con el Imperio; como gran jurista y experto en teología, comenzó un movimiento por el cual se consideraba guardián y defensor de las almas de toda la Cristiandad, mientras que los príncipes laicos eran solamente los defensores físicos de sus vasallos. Se reservaba así el derecho a intervenir en política dentro de los territorios cristianos, y respetando la capacidad de los Electores (tres de los cuales eran a su vez príncipes eclesiásticos) se afirmó en su derecho de ratificar esa elección (o no), pues el mismo Imperio procedía en principio y por su propia motivación a la Iglesia. Así, tras la muerte de Enrique VI en 1197, Inocencio III impuso su gran autoridad para erigirse en árbitro y juez de los pretendientes al trono. El posterior conflicto entre el ya usurpador Otón IV y Felipe Augusto de Francia (batalla del Domingo de Bouvines, en 1214), transformó definitivamente las relaciones entre papado e Imperio, dejando profundas huellas en las tierras alemanas y una configuración política e institucional que nos proponemos demarcar con el ilustrativo ejemplo de los condes de Mörs.One of the most important aspects of the foreign policy concerning Pope Innocent III was his relationship with the Empire; as great jurist and expert in theology himself, he began a movement by which he was considered guardian and defender of the souls of all Christendom, while the lay princes were only the way of physical defense of his subjects. He reserved the right to intervene in politics in Christian lands, and respecting the capacity of Electors (three of which were in turn princes of the Church) he stated his right to ratify that choice (or not), as the Empire itself came in principle and by their own motivation, from the Church. Thus, after the death of Henry VI in 1197, Innocent III imposed his great authority to establish himself as referee and judge of the pretenders to the throne. The subsequent conflict between the already usurper Otto IV and Philip Augustus of France (Battle of Bouvines, 1214), definitely transformed the relations between Papacy and Empire, leaving deep footprints in the German lands and a political and institutional setting that we propose to demarcate with the illustrative example of the counts of Mörs.Ciencias ReligiosasDerech

Rebel legions and their premeditated destruction: the case of Tetricus, Gallic emperor, compared in the sources

En este artículo se presenta el caso de las legiones romanas en el Imperio Gálico, el estado paralelo occidental durante la Anarquía Militar del siglo III ; tras asesinar a varios altos funcionarios y emperadores estas tropas habían llegado a un punto de indisciplina tal que el propio Tétrico decidió traicionar a su ejército para que fuese destruido y rendirse, buscando su salvación en la clemencia de Aureliano. Se analiza aquí ese episodio histórico y es comparado con otros dos casos similares, relacionados con la usurpación de Magnencio en Occidente y la conquista bizantina de África en tiempos de Justiniano.This article discusses the situation of the Roman legions in the Gallic Empire, the parallel western State that existed during the Military Anarchy of the Third Century. After killing some senior bureaucrats and emperors, these troops had become so undisciplined that Tetricus himself decided to betray his army so that it would be destroyed and surrender, seeking his own salvation in the mercy of Aurelian. This historical episode is analyzed and compared with two similar situations, the usurpation of Magnentius in the West and the Byzantine conquest of Africa in the time of Justinian

Comparison of feature representations in MRI-based MCI-to-AD conversion prediction

Alzheimer's disease (AD) is a progressive neurological disorder in which the death of brain cells causes memory loss and cognitive decline. The identification of at-risk subjects yet showing no dementia symptoms but who will later convert to AD can be crucial for the effective treatment of AD. For this, Magnetic Resonance Imaging (MRI) is expected to play a crucial role. During recent years, several Machine Learning (ML) approaches to AD-conversion prediction have been proposed using different types of MRI features. However, few studies comparing these different feature representations exist, and the existing ones do not allow to make definite conclusions. We evaluated the performance of various types of MRI features for the conversion prediction: voxel-based features extracted based on voxel-based morphometry, hippocampus volumes, volumes of the entorhinal cortex, and a set of regional volumetric, surface area, and cortical thickness measures across the brain. Regional features consistently yielded the best performance over two classifiers (Support Vector Machines and Regularized Logistic Regression), and two datasets studied. However, the performance difference to other features was not statistically significant. There was a consistent trend of age correction improving the classification performance, but the improvement reached statistical significance only rarely.Data collection and sharing for this project was funded by the Alzheimer's Disease Neuroimaging Initiative (ADNI) (National Institutes of Health Grant U01 AG024904) and DOD ADNI (Department of Defense award number W81XWH-12-2-0012). ADNI is funded by the National Institute on Aging, the National Institute of Biomedical Imaging and Bioengineering, and through generous contributions from the following: AbbVie, Alzheimer's Association; Alzheimer's Drug Discovery Foundation; Araclon Biotech; BioClinica, Inc.; Biogen; Bristol-Myers Squibb Company; CereSpir, Inc.; Eisai Inc.; Elan Pharmaceuticals, Inc.; Eli Lilly and Company; EuroImmun; F. Hoffmann-La Roche Ltd and its affiliated company Genentech, Inc.; Fujirebio; GE Healthcare; IXICO Ltd.; Janssen Alzheimer Immunotherapy Research & Development, LLC.; Johnson & Johnson Pharmaceutical Research & Development LLC.; Lumosity; Lundbeck; Merck & Co., Inc.; Meso Scale Diagnostics, LLC.; NeuroRx Research; Neurotrack Technologies; Novartis Pharmaceuticals Corporation; Pfizer Inc.; Piramal Imaging; Servier; Takeda Pharmaceutical Company; and Transition Therapeutics. J. Tohka's work was supported by the Academy of Finland and V. Gómez-Verdejo's work has been partly funded by the Spanish MINECO grant TEC2014-52289R, TEC2016-81900-REDT/AEI and TEC2017-83838-R

Multilayer N-doped graphene films as photoelectrodes for H2 evolution

[EN] Multilayer N-doped graphene photoelectrodes have been prepared following a straightforward one-step pyrolytic fabrication method. The N-doped graphene photoelectrodes have been demonstrated to work both as semitransparent electrodes and as efficient photoelectrocatalysts for H2 evolution at low bias. N-doped graphene photoelectrodes exhibited a constant H2 generation rate of 3.64 mmolh @1 cm2 at 0.2 V under 3443 Wm@2 irradiation for 17 h, reaching an applied-bias-compensated solar-to-hydrogen efficiency of 1.8%. The N-doped graphene photoelectrodes show light-intensity dependence as well as photocatalytic activity for H2 evolution in the UV/Vis spectral region. Impedance spectroscopy provides experimental evidence indicating that charge separation within N-doped graphene increases upon positive bias polarization of the photoelectrode.Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa, Grapas and CTQ2015-69153-C02-R1) and Generalitat Valenciana (Prometeo 2013-014) is gratefully acknowledged. J.A. also thanks the Universitat Politecnica de Valencia for a postdoctoral scholarship.García-Gómez, A.; Albero-Sancho, J.; García Gómez, H. (2017). Multilayer N-doped graphene films as photoelectrodes for H2 evolution. ChemPhotoChem. 1(9):388-392. https://doi.org/10.1002/cptc.201700049S3883921

Luminescence control in hybrid perovskites and their applications

[EN] Hybrid metal halide perovskites have emerged as promising semiconductor materials for photovoltaic applications as a consequence of their remarkable intrinsic optoelectronic properties and their compositional flexibility. However, these properties have also been found to be suitable for applications in other different fields. In particular, the photoluminescence properties of hybrid perovskites have demonstrated to give rise to efficient light emitting devices as well as lasing applications. In this manuscript we have reviewed the recent advances of hybrid perovskites in these fields paying attention to the compositional design of perovskites as a tool to modulate the luminescence properties of this class of devices.Financial support from the Spanish Ministry of Economy and Competitiveness (Severo Ochoa, and CTQ2015-69563-CO2-R1) and from the Generalitat Valenciana (Prometeo 2013-014) is gratefully acknowledged. J. A. also thanks the Universitat Politecnica de Valencia for a postdoctoral scholarship.Albero-Sancho, J.; García Gómez, H. (2017). Luminescence control in hybrid perovskites and their applications. Journal of Materials Chemistry C. 5(17):4098-4110. https://doi.org/10.1039/C7TC00714KS40984110517Kojima, A., Teshima, K., Shirai, Y., & Miyasaka, T. (2009). Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells. Journal of the American Chemical Society, 131(17), 6050-6051. doi:10.1021/ja809598rZhou, H., Chen, Q., Li, G., Luo, S., Song, T. -b., Duan, H.-S., … Yang, Y. (2014). Interface engineering of highly efficient perovskite solar cells. Science, 345(6196), 542-546. doi:10.1126/science.1254050Jeon, N. J., Noh, J. H., Yang, W. S., Kim, Y. C., Ryu, S., Seo, J., & Seok, S. I. (2015). Compositional engineering of perovskite materials for high-performance solar cells. Nature, 517(7535), 476-480. doi:10.1038/nature14133Muthu, C., Nagamma, S. R., & Nair, V. C. (2014). Luminescent hybrid perovskite nanoparticles as a new platform for selective detection of 2,4,6-trinitrophenol. RSC Adv., 4(99), 55908-55911. doi:10.1039/c4ra07884eFang, Y., Dong, Q., Shao, Y., Yuan, Y., & Huang, J. (2015). Highly narrowband perovskite single-crystal photodetectors enabled by surface-charge recombination. Nature Photonics, 9(10), 679-686. doi:10.1038/nphoton.2015.156Tan, Z.-K., Moghaddam, R. S., Lai, M. L., Docampo, P., Higler, R., Deschler, F., … Friend, R. H. (2014). Bright light-emitting diodes based on organometal halide perovskite. Nature Nanotechnology, 9(9), 687-692. doi:10.1038/nnano.2014.149Xing, G., Mathews, N., Lim, S. S., Yantara, N., Liu, X., Sabba, D., … Sum, T. C. (2014). Low-temperature solution-processed wavelength-tunable perovskites for lasing. Nature Materials, 13(5), 476-480. doi:10.1038/nmat3911Docampo, P., & Bein, T. (2016). A Long-Term View on Perovskite Optoelectronics. Accounts of Chemical Research, 49(2), 339-346. doi:10.1021/acs.accounts.5b00465Yang, D., Xie, C., Sun, J., Zhu, H., Xu, X., You, P., … Yu, S. F. (2016). Amplified Spontaneous Emission from Organic-Inorganic Hybrid Lead Iodide Perovskite Single Crystals under Direct Multiphoton Excitation. Advanced Optical Materials, 4(7), 1053-1059. doi:10.1002/adom.201600047Colella, S., Mazzeo, M., Rizzo, A., Gigli, G., & Listorti, A. (2016). The Bright Side of Perovskites. The Journal of Physical Chemistry Letters, 7(21), 4322-4334. doi:10.1021/acs.jpclett.6b01799Wehrenfennig, C., Liu, M., Snaith, H. J., Johnston, M. B., & Herz, L. M. (2014). Homogeneous Emission Line Broadening in the Organo Lead Halide Perovskite CH3NH3PbI3–xClx. The Journal of Physical Chemistry Letters, 5(8), 1300-1306. doi:10.1021/jz500434pWu, K., Bera, A., Ma, C., Du, Y., Yang, Y., Li, L., & Wu, T. (2014). Temperature-dependent excitonic photoluminescence of hybrid organometal halide perovskite films. Phys. Chem. Chem. Phys., 16(41), 22476-22481. doi:10.1039/c4cp03573aZhang, M., Yu, H., Lyu, M., Wang, Q., Yun, J.-H., & Wang, L. (2014). Composition-dependent photoluminescence intensity and prolonged recombination lifetime of perovskite CH3NH3PbBr3−xClxfilms. Chem. Commun., 50(79), 11727-11730. doi:10.1039/c4cc04973jAlbero, J., Asiri, A. M., & García, H. (2016). Influence of the composition of hybrid perovskites on their performance in solar cells. Journal of Materials Chemistry A, 4(12), 4353-4364. doi:10.1039/c6ta00334fQuan, L. N., Yuan, M., Comin, R., Voznyy, O., Beauregard, E. M., Hoogland, S., … Sargent, E. H. (2016). Ligand-Stabilized Reduced-Dimensionality Perovskites. Journal of the American Chemical Society, 138(8), 2649-2655. doi:10.1021/jacs.5b11740Xu, H., Sun, J., Qin, A., Hua, J., Li, Z., Dong, Y., … Tang, B. Z. (2006). Functional Perovskite Hybrid of Polyacetylene Ammonium and Lead Bromide:  Synthesis, Light Emission, and Fluorescence Imagining. The Journal of Physical Chemistry B, 110(43), 21701-21709. doi:10.1021/jp0646269Kawano, N., Koshimizu, M., Sun, Y., Yahaba, N., Fujimoto, Y., Yanagida, T., & Asai, K. (2014). Effects of Organic Moieties on Luminescence Properties of Organic–Inorganic Layered Perovskite-Type Compounds. The Journal of Physical Chemistry C, 118(17), 9101-9106. doi:10.1021/jp4114305Amat, A., Mosconi, E., Ronca, E., Quarti, C., Umari, P., Nazeeruddin, M. K., … De Angelis, F. (2014). Cation-Induced Band-Gap Tuning in Organohalide Perovskites: Interplay of Spin–Orbit Coupling and Octahedra Tilting. Nano Letters, 14(6), 3608-3616. doi:10.1021/nl5012992Filip, M. R., Eperon, G. E., Snaith, H. J., & Giustino, F. (2014). Steric engineering of metal-halide perovskites with tunable optical band gaps. Nature Communications, 5(1). doi:10.1038/ncomms6757Papavassiliou, G. C., Vidali, M.-S., Pagona, G., Mousdis, G. A., Karousis, N., & Koutselas, I. (2015). Effects of organic moieties on the photoluminescence spectra of perovskite-type tin bromide based compounds. Journal of Physics and Chemistry of Solids, 79, 1-6. doi:10.1016/j.jpcs.2014.11.018Perumal, A., Shendre, S., Li, M., Tay, Y. K. E., Sharma, V. K., Chen, S., … Demir, H. V. (2016). High brightness formamidinium lead bromide perovskite nanocrystal light emitting devices. Scientific Reports, 6(1). doi:10.1038/srep36733Niu, Y., Zhang, F., Bai, Z., Dong, Y., Yang, J., Liu, R., … Zhong, H. (2014). Aggregation-Induced Emission Features of Organometal Halide Perovskites and Their Fluorescence Probe Applications. Advanced Optical Materials, 3(1), 112-119. doi:10.1002/adom.201400403Yangui, A., Garrot, D., Lauret, J. S., Lusson, A., Bouchez, G., Deleporte, E., … Boukheddaden, K. (2015). Optical Investigation of Broadband White-Light Emission in Self-Assembled Organic–Inorganic Perovskite (C6H11NH3)2PbBr4. The Journal of Physical Chemistry C, 119(41), 23638-23647. doi:10.1021/acs.jpcc.5b06211Dai, J., Zheng, H., Zhu, C., Lu, J., & Xu, C. (2016). Comparative investigation on temperature-dependent photoluminescence of CH3NH3PbBr3and CH(NH2)2PbBr3microstructures. Journal of Materials Chemistry C, 4(20), 4408-4413. doi:10.1039/c6tc00563bAhmad, S., Baumberg, J. J., & Vijaya Prakash, G. (2013). Structural tunability and switchable exciton emission in inorganic-organic hybrids with mixed halides. Journal of Applied Physics, 114(23), 233511. doi:10.1063/1.4851715Gauthron, K., Lauret, J.-S., Doyennette, L., Lanty, G., Al Choueiry, A., Zhang, S. J., … Deleporte, E. (2010). Optical spectroscopy of two-dimensional layered (C_6H_5C_2H_4-NH_3)_2-PbI_4 perovskite. Optics Express, 18(6), 5912. doi:10.1364/oe.18.005912Yangui, A., Pillet, S., Mlayah, A., Lusson, A., Bouchez, G., Triki, S., … Boukheddaden, K. (2015). Structural phase transition causing anomalous photoluminescence behavior in perovskite (C6H11NH3)2[PbI4]. The Journal of Chemical Physics, 143(22), 224201. doi:10.1063/1.4936776Dohner, E. R., Jaffe, A., Bradshaw, L. R., & Karunadasa, H. I. (2014). Intrinsic White-Light Emission from Layered Hybrid Perovskites. Journal of the American Chemical Society, 136(38), 13154-13157. doi:10.1021/ja507086bAtourki, L., Vega, E., Marí, B., Mollar, M., Ait Ahsaine, H., Bouabid, K., & Ihlal, A. (2016). Role of the chemical substitution on the structural and luminescence properties of the mixed halide perovskite thin MAPbI3−xBrx (0 ≤ x ≤ 1) films. Applied Surface Science, 371, 112-117. doi:10.1016/j.apsusc.2016.02.207Kumawat, N. K., Tripathi, M. N., Waghmare, U., & Kabra, D. (2016). Structural, Optical, and Electronic Properties of Wide Bandgap Perovskites: Experimental and Theoretical Investigations. The Journal of Physical Chemistry A, 120(22), 3917-3923. doi:10.1021/acs.jpca.6b04138Yan, J., Zhang, B., Chen, Y., Zhang, A., & Ke, X. (2016). Improving the Photoluminescence Properties of Perovskite CH3NH3PbBr3-xClx Films by Modulating Organic Cation and Chlorine Concentrations. ACS Applied Materials & Interfaces, 8(20), 12756-12763. doi:10.1021/acsami.6b01303Gonzalez-Carrero, S., Galian, R. E., & Pérez-Prieto, J. (2015). Maximizing the emissive properties of CH3NH3PbBr3 perovskite nanoparticles. Journal of Materials Chemistry A, 3(17), 9187-9193. doi:10.1039/c4ta05878jD’Innocenzo, V., Srimath Kandada, A. R., De Bastiani, M., Gandini, M., & Petrozza, A. (2014). Tuning the Light Emission Properties by Band Gap Engineering in Hybrid Lead Halide Perovskite. Journal of the American Chemical Society, 136(51), 17730-17733. doi:10.1021/ja511198fWei, M., Chung, Y.-H., Xiao, Y., & Chen, Z. (2015). Color tunable halide perovskite CH3NH3PbBr3−Cl emission via annealing. Organic Electronics, 26, 260-264. doi:10.1016/j.orgel.2015.07.053Huang, H., Susha, A. S., Kershaw, S. V., Hung, T. F., & Rogach, A. L. (2015). Control of Emission Color of High Quantum Yield CH3NH3PbBr3Perovskite Quantum Dots by Precipitation Temperature. Advanced Science, 2(9), 1500194. doi:10.1002/advs.201500194Lv, X.-H., Liao, W.-Q., Li, P.-F., Wang, Z.-X., Mao, C.-Y., & Zhang, Y. (2016). Dielectric and photoluminescence properties of a layered perovskite-type organic–inorganic hybrid phase transition compound: NH3(CH2)5NH3MnCl4. Journal of Materials Chemistry C, 4(9), 1881-1885. doi:10.1039/c5tc04114gProtesescu, L., Yakunin, S., Bodnarchuk, M. I., Krieg, F., Caputo, R., Hendon, C. H., … Kovalenko, M. V. (2015). Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, and I): Novel Optoelectronic Materials Showing Bright Emission with Wide Color Gamut. Nano Letters, 15(6), 3692-3696. doi:10.1021/nl5048779Nedelcu, G., Protesescu, L., Yakunin, S., Bodnarchuk, M. I., Grotevent, M. J., & Kovalenko, M. V. (2015). Fast Anion-Exchange in Highly Luminescent Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, I). Nano Letters, 15(8), 5635-5640. doi:10.1021/acs.nanolett.5b02404Wei, S., Yang, Y., Kang, X., Wang, L., Huang, L., & Pan, D. (2016). Room-temperature and gram-scale synthesis of CsPbX3 (X = Cl, Br, I) perovskite nanocrystals with 50–85% photoluminescence quantum yields. Chemical Communications, 52(45), 7265-7268. doi:10.1039/c6cc01500jBekenstein, Y., Koscher, B. A., Eaton, S. W., Yang, P., & Alivisatos, A. P. (2015). Highly Luminescent Colloidal Nanoplates of Perovskite Cesium Lead Halide and Their Oriented Assemblies. Journal of the American Chemical Society, 137(51), 16008-16011. doi:10.1021/jacs.5b11199Palazon, F., Di Stasio, F., Akkerman, Q. A., Krahne, R., Prato, M., & Manna, L. (2016). Polymer-Free Films of Inorganic Halide Perovskite Nanocrystals as UV-to-White Color-Conversion Layers in LEDs. Chemistry of Materials, 28(9), 2902-2906. doi:10.1021/acs.chemmater.6b00954Jellicoe, T. C., Richter, J. M., Glass, H. F. J., Tabachnyk, M., Brady, R., Dutton, S. E., … Böhm, M. L. (2016). Synthesis and Optical Properties of Lead-Free Cesium Tin Halide Perovskite Nanocrystals. Journal of the American Chemical Society, 138(9), 2941-2944. doi:10.1021/jacs.5b13470Suta, M., Urland, W., Daul, C., & Wickleder, C. (2016). Photoluminescence properties of Yb2+ ions doped in the perovskites CsCaX3 and CsSrX3 (X = Cl, Br, and I) – a comparative study. Physical Chemistry Chemical Physics, 18(19), 13196-13208. doi:10.1039/c6cp00085aKim, Y.-H., Cho, H., Heo, J. H., Kim, T.-S., Myoung, N., Lee, C.-L., … Lee, T.-W. (2014). Multicolored Organic/Inorganic Hybrid Perovskite Light-Emitting Diodes. Advanced Materials, 27(7), 1248-1254. doi:10.1002/adma.201403751Era, M., Morimoto, S., Tsutsui, T., & Saito, S. (1994). Organic‐inorganic heterostructure electroluminescent device using a layered perovskite semiconductor (C6H5C2H4NH3)2PbI4. Applied Physics Letters, 65(6), 676-678. doi:10.1063/1.112265Hattori, T., Taira, T., Era, M., Tsutsui, T., & Saito, S. (1996). Highly efficient electroluminescence from a heterostructure device combined with emissive layered-perovskite and an electron-transporting organic compound. Chemical Physics Letters, 254(1-2), 103-108. doi:10.1016/0009-2614(96)00310-7Chondroudis, K., & Mitzi, D. B. (1999). Electroluminescence from an Organic−Inorganic Perovskite Incorporating a Quaterthiophene Dye within Lead Halide Perovskite Layers. Chemistry of Materials, 11(11), 3028-3030. doi:10.1021/cm990561tJaramillo-Quintero, O. A., Sanchez, R. S., Rincon, M., & Mora-Sero, I. (2015). Bright Visible-Infrared Light Emitting Diodes Based on Hybrid Halide Perovskite with Spiro-OMeTAD as a Hole-Injecting Layer. 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