We report measurements of the full intrinsic optical anisotropy of isolated single-wall carbon nanotubes (SWNTs). By combining absorption spectroscopy with transmission ellipsometry and polarization-dependent resonant Raman scattering, we obtain the real and imaginary parts of the SWNT permittivity from aligned semiconducting SWNTs dispersed in stretched polymer films. Our results are in agreement with theoretical predictions, highlighting the limited polarizability of excitons in a quasi-1D system.
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http://dx.doi.org/10.1103/PhysRevLett.98.147402 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
Semiconducting transition metal dichalcogenides (TMDs) possess exceptional photoelectronic properties, rendering them excellent channel materials for phototransistors and holding great promise for future optoelectronics. However, the attainment of high-performance photodetection has been impeded by challenges pertaining to electrical contact. To surmount this obstacle, we introduce a phototransistor architecture, in which the WS channel is connected with an alternating WS-WSe strip superstructure, strategically positioned alongside the source and drain contact regions.
View Article and Find Full Text PDFNanoscale Adv
December 2024
Institute of Research and Development, Duy Tan University Da Nang 550000 Vietnam
In this work, we present a comprehensive investigation into the electronic properties and contact behavior of γ-GeSe/GaSSe heterostructures using first-principles calculations. Two stacking configurations, γ-GeSe/SGaSe and γ-GeSe/SeGaS, are explored, both exhibiting semiconducting behavior with type-II and type-I band alignments, respectively. Notably, our results show that the band alignment transition in these heterostructures can occur spontaneously by simply altering the stacking configuration, eliminating the need for external factors.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Institute of Functional Nano & Soft Materials (FUNSOM), Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University, Suzhou, 215123, Jiangsu, PR China.
Silver bismuth sulfide nanocrystals (AgBiS NCs) embody a pioneering heavy-metal-free photovoltaic material renowned for its ultrahigh absorption coefficient, offering promising opportunities for advancing the field of ultra-thin and biocompatible solar cells. Currently, the fabrication of AgBiS NC photovoltaic devices relies on hot-injection synthesis and subsequent tedious ligand exchange, leading to high production cost, complex processes and environmental pollution. Here, we developed a direct-synthesis (DS) method without ligand-exchange for AgBiS NC semiconductive inks, significantly simplifying the material preparation and device fabrication processes.
View Article and Find Full Text PDFSmall
November 2024
Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK.
Nanofibrous active layers offer hierarchical control over molecular structure, and the size and distribution of electron donor:acceptor domains, beyond conventional organic photovoltaic architectures. This structure is created by forming donor pathways via electrospinning nanofibers of semiconducting polymer, then infiltrating with an electron acceptor. Electrospinning induces chain and crystallite alignment, resulting in enhanced light-harvesting and charge transport.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Electrostatic catalysis uses an external electric field (EEF) to rearrange the charge distribution to boost reaction rates and selectively produce certain reaction products in small-molecule reactions (e.g., Diels-Alder addition), requiring a 10 MV/cm field aligned with the reaction axis.
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