The influence of surface roughness on emission site density (ESD) is investigated for nanotube film emitters. An empirical expression for film emitters, [Formula: see text], where B is the intercept in the modified Fowler-Nordheim (FN) plots, A(CNT) the emission area of one site, and C related to the work function, is derived from the FN theory and experimentally proved. This expression effectively excludes the influence of electric field strength, being different from the conventional method of counting site numbers from emission patterns. By using this equation and emission patterns, variation in ESD, induced by the change in cathode-anode distance, is confirmed for film emitters with rough surfaces. This variation is ascribed to the change in screen-effect strength among emission sites. It is also found that the smaller gaps produce the higher emission uniformity and site densities for rough-surface film emitters.
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http://dx.doi.org/10.1088/0957-4484/20/27/275206 | DOI Listing |
Chem Sci
October 2024
Key Laboratory of Optoelectronic Technology and Systems (Ministry of Education), Chongqing University Chongqing 400044 China
Metal halide perovskites (MHPs) have been developed rapidly for application in light-emitting diodes (LEDs), lasers, solar cells, photodetectors and other fields in recent years due to their excellent photoelectronic properties, and they have attracted the attention of many researchers. Perovskite LEDs (PeLEDs) show great promise for next-generation lighting and display technologies, and the external quantum efficiency (EQE) values of polycrystalline thin-film PeLEDs exceed 20%, which is undoubtedly a big breakthrough in lighting and display fields. However, the toxicity and instabilities of lead-based MHPs remain major obstacles limiting their further commercial applications.
View Article and Find Full Text PDFNat Commun
January 2025
Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA.
Solutions for scalable, high-performance optical control are important for the development of scaled atom-based quantum technologies. Modulation of many individual optical beams is central to applying arbitrary gate and control sequences on arrays of atoms or atom-like systems. At telecom wavelengths, miniaturization of optical components via photonic integration has pushed the scale and performance of classical and quantum optics far beyond the limitations of bulk devices.
View Article and Find Full Text PDFChem Asian J
January 2025
Organometallics and Materials Chemistry Lab, Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502285, Telangana, India.
Fluorescence emission regulation is of great interest for its promising applications in various fields such as microscopy, chemical analysis, encryption, and sensing. Most studies focus on the regulation of the fluorescence emission process. However, the spectral separation of excitation and emission of fluorophores requires careful design of resonances to cover both emission and excitation wavelengths, which is a better choice to enhance fluorescence intensity.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
School of Materials Science and Engineering, Tianjin Key Laboratory of Metal and Molecular Materials Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tongyan Road 38, Tianjin, 300350, P. R. China.
Chiral hybrid organic-inorganic metal halides (HOMHs) hold great promise in broad applications ranging from ferroelectrics, spintronics to nonlinear optics, owing to their broken inversion symmetry and tunable chiroptoelectronic properties. Typically, chiral HOMHs are constructed by chiral organic cations and metal anion polyhedra, with the latter regarded as optoelectronic active units. However, the primary design approaches are largely constrained to regulation of general components within structural formula.
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