Cathy Yip’s Post

New paper out: "Band gap and THz optical adsorption of SnSe and SnSe2 nanosheets on graphene: Negative dielectric constant of SnSe". In this work we investigated the electronic and optical properties of the SnSe and SnSe2 structures as free-standing monolayers and in interfaces with graphene nanosheets. Our results suggest that the designed heterostructures are applicable in fast electronic devices at GHz to THz frequencies. https://lnkd.in/dmxPdNse 

Finally out in Nanophotonics! "Guiding light with surface exciton–polaritons in atomically thin superlattices" Single-molecule-thick layers of 2d-semiconductors have amazing optical properties. Light can be confined to very small volumes by such materials, with promising applications for ultra compact devices. We study light in superlattices made of multiple WS2 monolayers, and demonstrate that superlattices can improve and allow better tunability of the light behavior. This was possible thanks to the great work of the co-authors,T. V. Raziman, Sandra de Vega, Javier García de Abajo, and Alberto G. Curto If you are interested, please read the full paper here; https://lnkd.in/ewT4NhTG #Superlattice #Exciton–polaritons #2D-semiconductors #WS2 #Van der Waals heterostructures

I am excited to share our latest research findings in our newly published paper! Using first-principles GW-BSE calculations, we have demonstrated the significant influence a graphene layer has on the optical properties of a WS2 monolayer. Our study shows that beyond the simple expected dielectric effects which affect the position and intensity of absorption peaks, the selection rules, and even the shape of the absorption peaks and the exciton wavefunctions are altered by the presence of the graphene layer. A special thanks to Daniel Hernangómez Pérez and Sivan Refaely Abramson! Explore our findings in the full article: https://lnkd.in/d_BpCPjG

Discover AquAffirm’s Revolutionary Thin-film Planar Electrodes! Engineered with precision, our electrodes feature sputtered gold on a PET substrate, encapsulated by screen-printed hydrophobic ink. Ideal for #SensorDevelopment, #ElectrochemistryResearch, and #Microfluidics. To find out more email us at info@aquaffirm.com. Step into the future of biosensing with AquAffirm! #Electrode #Biosensing

We are proud to announce that our recent paper, titled "Graphene Schottky barrier diode acting as a semi-transparent contact to n-GaN" (AIP Advances 14, 075312 (2024), https://lnkd.in/d39zVU8v), has been recognized as noteworthy by the AIP Editors and therefore, has been selected to be featured in a special collection of Editor's Pick articles. In this article, we demonstrated the successful development of graphene Schottky barrier diodes (Gr SBDs) as efficient semi-transparent contacts to n-GaN. Gr/GaN diodes were used for detailed investigations of deep traps present in n-GaN grown by MOVPE. The results showed that the Steady State Photo Capacitance (SSPC) and Deep Level Optical Spectroscopy (DLOS) spectra obtained for Gr SBDs are in excellent agreement with Ni-based semi-transparent contacts to n-GaN that were used for comparison. Deep trap levels were identified at Ec-3.3 eV, Ec-2.6 eV, and Ec-1.84 eV for Ni SBD, and at Ec-3.3 eV and Ec-2.6 eV for Gr SBD. Finally, the optical capture cross-section data (σ0) derived from DLOS were fitted using the Lucovsky model where no lattice relaxation for all deep traps observed in the study were assumed.

Photoluminescence and Luminescence Quantum Yield Test System 📍LQ-100X-PL is NIST traceable and with a compact design. The size is 502.4mm(L) x 322.5mm(W) x 352mm(H), equipped a 4-inch outer diameter PTFE integrating sphere. LQ-100X-PL makes the glovebox integration possible. 📍Using advanced instrument control programs, in situ time PL spectral analysis can be performed, producing 2D and 3D graphs simultaneously. This will greatly help users complete material characterization more quickly. 📍The outstanding optical design expand the spectrum wavelength. It covers the wavelength range from can be extened to 1700nm. LQ-100X-PL is compatible with powder, solution and thin film samples. #SolarSimulator #SunSimulator #QuantumEfficiency #Perovskite #SolarCell #Photoluminescence

In this interesting study, the influence of the rotation of nanoparticles on their luminescence is discussed. The sophisticated measurements were made possible by the stable, pulsation-free and reproducible flow of a Nemesys high-pressure module 2600N from CETONI GmbH - Automation and Microsystems. Thanks to the authors Markus Johann Schmidt and Thomas Rösgen for the fantastic work. #WeSupportYou #CETONIscholar #Nemesys https://lnkd.in/dewMEqN2

https://lnkd.in/dbcP46JE Multilayered van der Waals (vdW) vertical heterostructures are a promising avenue of combining different 2D materials to achieve desirable properties for numerous optoelectronic applications. To improve our understanding on how the stacking order can affect the physical properties of these systems, we present a density functional theory study of the energetic, electronic, and optical properties of graphene (Gr) - transition-metal dichalcogenides (TMDs) vdW heterostructures, namely, monolayer (graphene, MoS2, WS2), bilayer, and tetralayer systems.

🔬 Exciting News in Mid-Infrared Sensing! 🌐 We are thrilled to share the publication of our new paper titled "Mid-infrared interferometry with non-adiabatic tapered ZBLAN optical fiber" in Optica Optics Express. This work, in collaboration with Le Verre Fluoré, introduces the first-ever non-adiabatic tapered single-mode zirconium fluoride optical fiber sensor. Overcoming fabrication challenges like crystallization and low glass transition temperature, we achieved a remarkably small waist diameter without visible crystallization, demonstrating all-fiber interferometry with fluoride glasses. The paper delves into both theoretical insights and experimental validations, demonstrating the sensor's potential for diverse sensing applications within the mid-infrared spectral range. Read the full paper: https://lnkd.in/dCdBs2JJ In this post, the longitudinal view of the non-adiabatic tapered optical fiber, during the fabrication process. #Optics #SensingTechnology #MidInfrared #OpticsExpress #Fluoride #OpticalFiber

Piezoelectric phase shifter in Michelson interferometer: The principle of Michelson interferometer is that a beam of incident light is divided into two beams through the spectroscope, and each is reflected back by the corresponding plane mirror, because the two beams of light have the same frequency, the same vibration direction and the constant phase difference (that is, meet the interference conditions), so interference can occur. The different optical paths of the two beams in the interference can be achieved by adjusting the length of the interference arm and changing the refractive index of the medium, so that different interference patterns can be formed. The interference fringes of equal thickness and equal inclination can be generated by adjusting the interferometer. The principle can be used to develop a variety of measuring instruments. The system uses the core tomorrow P63.Z piezoelectric nanopositioning platform as a phase shifter, the phase shift stroke is 0~6.8μm, the phase shift resolution can reach 0.1nm, the response speed of the full stroke 6.8μm motion range is 0.3ms, and the nanoscale step scanning speed will be faster. https://lnkd.in/gBF4JAUi