Nanowerk December 3, 2024 Although hybrid graphene-colloidal PbS quantum dots (QDs) phototransistors are promising to overcome the geometrical restrictions of photodetectors to flat substrates, the experimental demonstration of their application to curved surfaces remains elusive. Researchers in Switzerland demonstrated the seamless integration of an infrared photodetector to a polymer optical fiber (POF), by wrapping graphene around the POF of 1 mm in diameter and, inkjet printing of PbS QDs onto the curved surface. The device acted as a functional coating and detected infrared light propagating through the POF without interrupting the waveguide. The ink supported drop-on-demand, and was colloidally stable […]
Tag Archives: Infrared light
Researchers demonstrate new way to ‘squeeze’ infrared light
Science Daily June 10, 2024 Recent theoretical studies have suggested that transition metal perovskite oxide membranes can enable surface phonon polaritons in the infrared range with low loss and much stronger subwavelength confinement than bulk crystals. Such modes, however, have not been experimentally observed so far. An international team of researchers (USA – North Carolina State University, Lawrence Berkeley National Laboratory, Stanford University, SLAC National Accelerator Laboratory, Switzerland) studied the phonon polaritons in a 100 nm thick freestanding crystalline membrane of SrTiO3 transferred on metallic and dielectric substrates. They observed a symmetric-antisymmetric mode splitting which gave rise to epsilon-near-zero and Berreman […]
Copper-doped tungstic acid nanocrystals transform infrared light conversion
Nanowerk September 13, 2023 The technology to utilize the full spectrum of solar radiation is still in its infancy as conventional methods constrain their all-solar response. Researchers in Japan have proposed using – submerged photosynthesis of crystallites (SPsC). They showed that strategic doping with copper and oxygen vacancies can induce opto-critical phases from the non-stoichiometric tungstic acids. These opto-critical phases enabled a dynamic equilibrium shift in lattice defect stabilization, facilitating an unprecedented whole solar wavelength response. The response manifested photo-assisted water evaporation, and photo-electrochemical characteristics. According to the researchers their strategy of harnessing all-solar energy, the one-pot SPsC strategy, may […]
Scientists demonstrate new, improved way to make infrared light, with quantum dots
Phys.org September 6, 2023 In the visible spectrum, electroluminescence from colloidal quantum dots is highly efficient, wavelength tunable and cost effective, which motivates using the same approach in the infrared. Despite the promising performances of colloidal quantum dots light-emitting diodes in the near-infrared, mid-infrared devices show quantum efficiencies of about 0.1% due to the much weaker emission. These devices relied exclusively on the interband transition, restricting the possible materials. Researchers at the University of Chicago showed electroluminescence at 5 µm using the intraband transition between 1Se and 1Pe states within the conduction band of core–shell HgSe–CdSe colloidal quantum dots. The 4.5% […]
Researchers use infrared light to wirelessly transmit power over 30 meters
Science Daily August 30, 2022 Researchers in South Korea used an erbium-doped fiber amplifier optical power source with a central wavelength of 1550 nm. and wavelength division multiplexing filter that created a narrowband beam with optical power within the safety limits for free space propagation. They optimized distributed laser charging which enables self-alignment without tracking processes and automatically shifts to a safe low power delivery mode if an object or a person blocks the line of sight. They incorporated a spherical ball lens retroreflector in the receiver unit to facilitate 360-degree transmitter-receiver alignment, which maximized the power transfer efficiency. The […]