Lake Shore Cryotronics’ Post

Happy Friday! Here's an article that delves into the use of ferroionic 2D materials in electro-optic tuning, a component of silicon photonics. A valuable read for those following the field: https://lnkd.in/g-P5Q2vN #photonics #siliconphotonics

Brighter Perovskite LEDs Pave Way for Thin-Film Diode Lasers A research team from imec has developed perovskite-based LEDs that emit light 1000× brighter than OLEDs. According to the researchers, the advancement is a pivotal milestone toward a perovskite injection laser, which promises advances in image projection, environmental sensing, and medical diagnostics, among other applications. Perovskite materials are well known for their potential in photovoltaic technology, though perovskites also carry potential as a light amplifier for thin-film laser diodes. Perovskites’ optoelectrical properties, low-cost processability, and efficient charge transport make it a strong candidate for light emission applications like LEDs. However, perovskite LEDs (PeLEDs) must be able to achieve electrically excited amplified spontaneous emission (ASE) before they can serve as a gain medium for perovskite laser diodes. In PeLEDs, the requirement for high conductivity conflicts with the need for high net modal gain of the device stack, hampering ASE. While perovskites can withstand very high current densities, they have yet to be used for laser operation with the emission of high-intensity coherent light. When the imec team used 2.3-ns optical pulses at 77 K on the PeLED, the device demonstrated ASE with a threshold of 9.1 μJ/cm2. Upon sub-microsecond electrical excitation at 77 K of the same device, the PeLED realized current densities >3 kA/cm2, with irradiance values >40 W/cm2. Co-pumping the PeLED with optical pulses that were synchronized with the leading edge of an intense electrical pulse reduced the ASE threshold by 1.2 ± 0.2 μJ/cm2, demonstrating that electrically injected carriers contributed to optical gain. In contrast to III-V crystalline LEDs, OLEDs can be precisely designed and dimensioned, as single components or in arrays, into any target application without the need of hetero-assembly. However, their maximum brightness remains limited. The light power density of OLEDs remains about 300× smaller than that of III-V LEDs. Also, none of today’s thin-film light sources, including OLEDs, can be brought to lasing by electrical pumping. To demonstrate the feasibility of a perovskite semiconductor optical amplifier, the researchers probed the PeLED with 1 μs-long optical excitation. They observed continuous wave ASE at a threshold of 3.8 kW/cm2. The team also showed that intense electrical pulses can generate electroluminescence brightness levels close to half the irradiance produced by continuous wave optical pumping at the ASE threshold. The PeLED architecture developed by imec represents an important step toward achieving perovskite semiconductor optical amplifiers and perovskite injection lasers. Nature Photonics (https://lnkd.in/e2kTYEAn).

Current Situation And Hot Spots Of Microwave Signal Generation In Microwave Optoelectronics Microwave optoelectronics, as the name suggests, is the intersection of microwave and optoelectronics. Microwaves and light waves are electromagnetic waves, and the frequencies are many orders of magnitude different, and the components and technologies developed in their respective fields are very different. In combination, we can take advantage of each other, but we can get new applications and characteristics that are difficult to realize respectively. Optical communication is a prime example of the combination of microwaves and photoelectrons. Early telephone and telegraph wireless communications, the generation, propagation and reception of signals, all used microwave devices. Low frequency electromagnetic waves are used initially because the frequency range is small and the channel capacity for transmission is small. The solution is to increase the frequency of the transmitted signal, the higher the frequency, the more spectrum resources. But the high frequency signal in the air propagation loss is large, but also easy to be blocked by obstacles. If the cable is used, the loss of the cable is large, and long-distance transmission is a problem. The emergence of optical fiber communication is a good solution to these problems. Optical fiber has very low transmission loss and is an excellent carrier for transmitting signals over long distances. The frequency range of light waves is much greater than that of microwaves and can transmit many different channels simultaneously. Because of these advantages of optical transmission, optical fiber communication has become the backbone of today’s information transmission. Optical communication has a long history, research and application are very extensive and mature, here is not to say more. This paper mainly introduces the new research content of microwave optoelectronics in recent years other than optical communication. #Optical #photonics #semiconductor #Optics #opticalcenter #SiliconPhotonics #photodetectors #optomechanics #laser Read More: https://lnkd.in/eV6BhG29

Photonics Breakthrough: Tiny Chip Generates High-Quality Microwave Signals. Researchers create a compact, all-optical device with the lowest microwave noise ever achieved for an integrated chip. A high-level schematic of the photonic integrated chip, developed by the Gaeta lab, for all-optical optical frequency division, or OFD – a method of converting a high-frequency signal to a lower frequency - https://lnkd.in/g3tEqbGu #photonics

Over the past few years, #graphene nanoribbons (GNRs) have gained increasing attention and have become attractive candidates for carbon-based nanoelectronics. GNRs represent a frontier in carbon nanomaterial research, offering unique properties and opportunities for technological innovation in electronics, photonics, and energy storage. Properties of Graphene Nanoribbons : GNRs display a rich array of electronic and optical properties due to their unique quantum confinement and edge effects. Semiconducting GNRs feature remarkable tunability in their bandgaps, making them ideal for constructing nanoscale transistors and logic devices. This tunability allows for precise control over the flow of charge carriers, facilitating the development of high-performance electronic circuits. GNRs also exhibit exceptional optical characteristics, characterized by strong light-matter interactions and high absorption coefficients. These properties make GNRs highly suitable for various photonic and optoelectronic applications, including photodetectors, solar cells, and light-emitting devices. The ability to tailor GNRs' electronic and optical properties at the nanoscale opens up new avenues for the advancement of next-generation electronic and photonic technologies. #graphene #Graphenenanoribbons #GNRs #Electronics #Photonics

"Graphene plasmon polaritons are a class of hybrid quasi-particles with advantageous optoelectronic properties. These particles have proved promising for the development of miniaturized nanoscale circuits that operate in the terahertz and mid-infrared regions of the electromagnetic spectrum. These terahertz circuits could potentially process information at remarkable speeds, thus contributing to the further advancement of electronics. Despite the potential of graphene plasmon polaritons for realizing nanoscale terahertz circuits, existing techniques have proved ineffective in integrating the electronic components necessary to control polariton signals." #grapheneplasmonpolaritons #optoelectronic #nanoscalecircuits #terahertzcircuits

Happy to announce the seminar of Dr. Prasana Sahoo, who is visiting the Aachen Graphene & 2D Materials Center from Indian Institute of Technology, Kharagpur. Dr. Prasana Sahoo who will speak on “Exotic 2D Lateral Heterostructures and Optoelectronic Devices.” ABSTRACT: Atomically thin layered materials such as graphene and transition metal dichalcogenides (TMDs) have opened a new and rich field with exotic physical properties and exciting potential applications in the “flatland”. There are enormous possibilities in combining diverse 2D materials for the unique design of ultra-smart and flexible optoelectronic devices, including transistors, light-emitting diodes, photovoltaics, photodetectors, and quantum emitters. Considerable efforts have been devoted to the van der Waals vertical hetero-integration of different 2D layered materials. On the other hand, lateral heterostructure can be fabricated only via direct growth. It can offer exciting opportunities for engineering the formation, confinement, and transport of electrons, holes, exciton, phonon, and polariton. We reported the direct fabrication of seamless, high-quality TMDs lateral heterostructures and superlattices in the chemical-vapor-deposition process, only changing the reactive gas environment in the presence of water vapor. Our novel approach offers greater flexibility for the continuous growth of multi-junction TMDs lateral heterostructures/superlattices, controlled 1D interfaces, alloying, and layer numbers. The extent of the spatial modulation of individual TMD domains and their optical and electronic transition characteristics across the heterojunctions are studied in detail. Electrical transport measurements revealed diode behaviour across the 2D lateral junctions, promising for electroluminescence at room temperature. Using photon energy-resolved photoconductivity mapping, long-term carrier accumulation in MoS2-WS2 lateral heterostructures was observed. At the onset of photo-excitation, local carrier density was increased by two orders of magnitude and persisted for up to several days. Temperature-dependent photoluminescence from neutral exciton, trion, and defect-bound exciton provides a better understanding of the optical properties of these as-grown 2D lateral heterostructures. These studies will further supplement the quantitative evaluation of the optical properties of various 2D heterostructures to develop more complex and atomically thin superlattices and exotic 2D quantum devices. Furthermore, the performance of most 2D heterostructure-based devices falls far below the predicted values owing to several intrinsic and extrinsic factors. These significant issues will also be discussed.   The visit has been co-organized by Lutz Waldecker and Satender Kataria.

🔬 Exciting News! 📚 Just Published: "Low-Temperature Dielectric Study and Photoconductive Analysis of ZnO/NiO Composite Material" with an impact factor of 5.2 (Q1) 🌐 I am thrilled to share the findings of our latest research! 🎓 Our team utilized the sol-gel process to synthesise a ZnO/NiO composite material, exploring its unique properties. 🧪 Key Highlights: 🔍 X-ray diffraction (XRD) & scanning electron microscopy (SEM) confirmed the presence of ZnO nanoparticles and NiO sheets. The composite material exhibited two distinct crystalline phases: NiO (face-centred cubic) and ZnO (hexagonal), with an average crystallite size of 19.0 nm. 🎨 Photoluminescence (PL) spectroscopy showcased band edge emission at 393 nm, suggesting potential applications in optoelectronics. 🌐 Low-temperature dielectric studies revealed excellent performance at high frequencies, making it ideal for high-frequency microwave devices. ⚡ Enhanced electrical conductivity and photoconductivity compared to pure ZnO and NiO, positioning it as a promising candidate for solar cells, optical switches, and photodetectors. 📈 Impedance spectroscopy uncovered two dielectric relaxation processes related to bulk and grain boundary, providing insights into the material's behaviour. 👩🔬 Our findings suggest that the composite material, with a responsivity of 0.86 mA/Watt, holds great potential for various optoelectronic applications, outperforming pure NiO. 🔗 Check out the full publication for an in-depth exploration of the study: [https://lnkd.in/dMyZ7qmF ] I am excited to contribute to the field of materials science and explore the potential applications of this innovative composite material! 🌟 #MaterialsScience #Research #Optoelectronics #Innovation #SciencePublication #ZnONiOComposite

📢 We are thrilled to announce the publication of our groundbreaking research in the prestigious journal Nano Letters, entitled "Electronic Structure of Isolated Graphene Nanoribbons in Solution Revealed by Two-Dimensional Electronic Spectroscopy"! Our study reveals the electronic structure of isolated graphene nanoribbons (GNRs) in solution using two-dimensional electronic spectroscopy. This technique allows us to probe the band structure of GNRs with unprecedented precision, providing a comprehensive understanding of their electronic properties. Key findings: 👉 We demonstrate the existence of distinct electronic states within the band gap of GNRs, opening up new possibilities for their applications in optoelectronics and other fields. 👉 We identify a strong correlation between the GNR structure and its electronic properties, providing guidance for the design of GNR-based devices with tailored functionalities. 👉 We develop a theoretical framework to explain the observed electronic structure, validating our experimental findings and providing a deeper understanding of GNRs in solution. This work is a significant advancement in our understanding of isolated GNRs, paving the way for their further development and potential applications. The work has been made possible also thanks to the GEMINI interferometer by NIREOS! DOI: https://lnkd.in/dP-XbRaq #Graphene #Nanoribbons #ElectronicStructure #TwoDimensionalSpectroscopy #Optoelectronics #DeviceApplications Lucia Ganzer, Mattia Russo, Antonio Perri, Gabriel José de la Cruz Valbuena, Cosimo D'Andrea, Giulio Cerullo

Leveraging the higher quality of optical electronics, researchers have created a low-noise microwave oscillator using photonics. https://bit.ly/3x9TKPG