Thermionic emission relies on the low work function and negative electron affinity of the, often functionalized, surface of the emitting material. However, there is little understanding of the interplay between thermionic emission and temperature-driven dynamic surface transformation processes as these are not represented on the traditional Richardson-Dushman equation for thermionic emission. Here, we show a new model for thermionic emission that can reproduce the effect of dynamic surface changes on the electron emission and correlate the components of the thermionic emission with specific surface reconstruction phases on the surface of the emitter. We use hydrogenated <100> single-crystal and polycrystalline diamonds as thermionic emitters to validate our model, which shows excellent agreement with the experimental data and could be applicable to other emitting materials. Furthermore, we find that tailoring the coverage of specific structures of the C(100)-(2 × 1):H surface reconstruction could increase the thermionic emission of diamond by several orders of magnitude.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acsami.0c01677 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
High-resolution cryo-EM using a common LaB 120-keV electron microscope equipped with a sub-200-keV direct electron detector.
Sci Adv
January 2025
Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Clayton, VIC, Australia.
High-resolution cryo-electron microscopy (cryo-EM) requires costly 200- to 300-keV cryo-transmission electron microscopes (cryo-TEMs) with field emission gun (FEG) sources, stable columns, constant-powered lenses, autoloader, and direct electron detectors (DED). Recent advances in 100-keV imaging with the emergence of sub-200-keV optimized DED technology promises the development of more affordable cryo-TEMs. So far, 100-keV imaging has required microscopes with FEG sources.
View Article and Find Full Text PDFPhosphorus-based heterojunction tunnel field-effect transistors: from atomic insights to circuit renovations.
Phys Chem Chem Phys
December 2024
Department of Electrical Engineering, College of Technical and Engineering, West Tehran Branch, Islamic Azad University, Tehran 1461944563, Iran.
Tunnel field-effect transistors (TFETs) are gaining interest for low-power applications, but challenges like poor drive current, delayed saturation, and ambipolarity can hinder their performance. This work proposes a dopingless heterojunction TFET (DL-HTDET) utilizing advanced materials, all based on phosphorus, to address these issues. Our approach involves a comprehensive and accurate analysis of the DL-HTDET's behavior.
View Article and Find Full Text PDFElectron Loss and Dissociation Pathways of a Complex Dicarboxylate Dianion: EDTA.
J Phys Chem A
December 2024
Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom.
Photoelectron imaging of the doubly deprotonated ethylenediaminetetraacetic acid dianion (EDTA) at variable wavelengths indicates two electron loss pathways: direct detachment and thermionic emission from monoanions. The structure of EDTA is also investigated by electronic structure calculations, which indicate that EDTA has two intramolecular hydrogen bonds linking a carboxylate and carboxylic acid group at either end of the molecular backbone. The direct detachment feature in the photoelectron spectrum is very broad and provides evidence for a dissociative photodetachment, where decarboxylation occurs rapidly after electron loss.
View Article and Find Full Text PDFThermionic Emission in Artificially Structured Single-Crystalline Elemental Metal/Compound Semiconductor Superlattices.
Adv Mater
December 2024
Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, 560064, India.
Metal/semiconductor superlattices represent a fascinating frontier in materials science and nanotechnology, where alternating layers of metals and semiconductors are precisely engineered at the atomic and nano-scales. Traditionally, epitaxial metal/semiconductor superlattice growth requires constituent materials from the same family, exhibiting identical structural symmetry and low lattice mismatch. Here, beyond this conventional constraint, a novel class of epitaxial lattice-matched metal/semiconductor superlattices is introduced that utilizes refractory hexagonal elemental transition metals and wide-bandgap III-nitride semiconductors.
View Article and Find Full Text PDFCarboxymethyl cellulose/graphene oxide nanocomposite semiconductor for potential energy applications.
Int J Biol Macromol
January 2025
Institute of Engineering, Science, and Technology, Universidade Federal dos Vales do Jequitinhonha e Mucuri/UFVJM, Av. 01, 4050 Cidade Universitária, 39440-039 Janaúba, MG, Brazil; Pos-Graduate Program of Chemistry from Universidade Federal dos Vales do Jequitinhonha e Mucuri/UFVJM, Av. 01, 4050 Cidade Universitária, 39440-039 Janaúba, MG, Brazil. Electronic address:
The present research produced a new nanocomposite based on carboxymethyl cellulose (CMC) and graphene oxide (GO) for application in energy devices. A modified Hummers' method and two modifiers (UV radiation and heat temperature) were used. The nanocomposite was characterized by spectroscopies (FTIR, RAMAN, UV Vis), X-ray diffraction, morphological (SEM, TEM, DLS), and surface charge (ZP).
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!