Search results for "electronics"

Holographic Recording of Surface Relief Gratings on As40S60-xSex Thin Films

2015

The studies of direct holographic recording of the surface relief gratings on amorphous As40S60−xSex thin films are presented. These gratings were created upon exposure to polarized laser beams of various wavelengths (λ = 473 – 650 nm). The orthogonally ±45° linearly polarized light beams were used for recording. The surface structure of the relief gratings was investigated by atomic force microscopy. The influence of laser beam wavelength and spatial frequency of the gratings recorded (grating period ?) on the surface relief gratings formation for every composition was examined.

Photoinduced direct surface relief formation in amorphous As40S15Se45 films

2013

Abstract The surface relief grating formation in As40S15Se45 films under He–Ne laser wave-length λ = 0.6328 μm light influence was examined. The obtained experimental results showed the strong dependence of photoinduced surface relief depth on illumination dose and film thickness during holographic recording from film side as well as from glass substrate side. The surface relief grating profile over the thickness range 0.13

Dynamically Doped White Light Emitting Tandem Devices

2013

Solution-processed, salt-containing, blue and orange light-emitting layers lead to efficient white light-emitting devices when arranged in a tandem configuration separated by a thin metal layer.

Highly Efficient Thermally Co-evaporated Perovskite Solar Cells and Mini-modules

2020

The rapid improvement in the power conversion efficiency (PCE) of perovskite solar cells (PSCs) has prompted interest in bringing the technology toward commercialization. Capitalizing on existing industrial processes facilitates the transition from laboratory to production lines. In this work, we prove the scalability of thermally co-evaporated MAPbI3 layers in PSCs and mini-modules. With a combined strategy of active layer engineering, interfacial optimization, surface treatments, and light management, we demonstrate PSCs (0.16 cm2 active area) and mini-modules (21 cm2 active area) achieving record PCEs of 20.28% and 18.13%, respectively. Un-encapsulated PSCs retained ∼90% of their initial…

Efficient, 23%, Solution-Processed Perovskite Tandem Cells

2019

In this issue of Joule, Palmstrom and coworkers present efficient solution-processed two-terminal solar cells employing two metal halide perovskite-based absorbers. The key to this achievement is 2-fold: the deposition of a thin yet robust transparent conductor in between the two sub-cells allows solution processing of the back-cell and enables efficient and local charge recombination. Furthermore, the insertion of large cations reduces halide segregation and enables a higher open-circuit voltage and stability for the high-band-gap sub-cell.

Fully Evaporated High Efficiency Single Junction and Tandem Perovskite based Solar Cells.

2018

Chip-to-chip plasmonic interconnects and the activities of EU project NAVOLCHI

2012

In this paper, the chip-to-chip interconnection architecture adopted by the EU-project NAVOLCHI are discussed. The plasmonic physical layer consisting of a plasmonic nanoscale laser, a modulator, an amplifier and a detector is introduced. Current statuses of the plasmonic devices are reviewed.

Femtosecond exciton dynamics in WSe2 optical waveguides

2020

Van-der Waals (vdW) atomically layered crystals can act as optical waveguides over a broad range of the electromagnetic spectrum ranging from Terahertz to visible. Unlike common Si-based waveguides, vdW semiconductors host strong excitonic resonances that may be controlled using non-thermal stimuli including electrostatic gating and photoexcitation. Here, we utilize waveguide modes to examine photo-induced changes of excitons in the prototypical vdW semiconductor, WSe2, prompted by femtosecond light pulses. Using time-resolved scanning near-field optical microscopy we visualize the electric field profiles of waveguide modes in real space and time and extract the temporal evolution of the op…

Impact of pump wavelength on terahertz emission of a cavity-enhanced spintronic trilayer

2018

We systematically study the pump-wavelength dependence of terahertz pulse generation in thin-film spintronic THz emitters composed of a ferromagnetic Fe layer between adjacent nonmagnetic W and Pt layers. We find that the efficiency of THz generation is essentially at for excitation by 150 fs pulses with center wavelengths ranging from 900 to 1500 nm, demonstrating that the spin current does not depend strongly on the pump photon energy. We show that the inclusion of dielectric overlayers of TiO2 and SiO2, designed for a particular excitation wavelength, can enhance the terahertz emission by a factor of of up to two in field.

Tuning the Ultrafast Response of Fano Resonances in Halide Perovskite Nanoparticles

2020

International audience; The full control of the fundamental photophysics of nanosystems at frequencies as high as few THz is key for tunable and ultrafast nanophotonic devices and metamaterials. Here we combine geometrical and ultrafast control of the optical properties of halide perovskite nanoparticles, which constitute a prominent platform for nanophotonics. The pulsed photoinjection of free carriers across the semiconducting gap leads to a subpicosecond modification of the far-field electromagnetic properties that is fully controlled by the geometry of the system. When the nanoparticle size is tuned so as to achieve the overlap between the narrowband excitons and the geometry-controlled…