Nanowerk March 8, 2022 In thermoelectric materials the hot side can be easily obtained by excess heat. Since thermoelectric voltage is proportional to the temperature difference between the hot and cold sides, efficient passive cooling to increase the temperature gradient is of critical importance. Researchers in Japan have designed a magnetic hybrid system where radiative cooling occurs at the top, as heat is lost from a material in the form of infrared radiation, while solar radiation is absorbed at the bottom. They demonstrated this concept by using the spin Seebeck effect. The device shows the highest thermoelectric voltage when both […]
Tag Archives: Solar energy
Sunlight could be used to power lasers
Phys.org January 25, 2022 Turning the incoherent energy supply provided by the Sun into a coherent laser beam would overcome several of the practical limitations inherent in using sunlight as a source of clean energy. An international team of researchers (France, USA – University of Notre Dame, Italy, Mexico) proposed and designed a bio-inspired blueprint for a novel type of laser with the aim of upgrading unconcentrated natural sunlight into a coherent laser beam. They proposed a laser medium comprised of molecular aggregates inspired by the architecture of natural photosynthetic complexes which exhibit a very large internal efficiency in harvesting […]
N-type conductive tin sulfide thin films: Towards environmentally friendly solar cells
Science Daily December 13, 2021 An international team of researchers (Japan, USA – National Renewable Energy Laboratory) has fabricated n-type conductive SnS thin films by impurity doping. Conventional SnS thin films are usually p-type conductive. Thus, SnS thin-film solar cells have been fabricated using a pn heterojunction with p-type SnS thin film and other n-type semiconductor thin films, such as CdS. However, the conversion efficiency of such heterojunction devices is approximately 5%. The SnS thin-film solar cells employing a pn homojunction, which uses SnS thin films for both p-type and n-type layers, is expected to exhibit higher conversion efficiency. Utilizing […]
Researchers create nanoparticle paste to make perovskite solar cells more efficient
Nanowerk September 10, 2021 Large-scale and low-cost approaches for creating functional nanostructures are still not developed. An international team of researchers (Russia, Italy) has developed a method to create mesoporous electron transport layer based on optically resonant silicon nanoparticles incorporated into TiO paste to be applied for perovskite (MAPbI) solar cell. The inclusion of Mie-resonant silicon nanoparticles helps to improve light absorption by a perovskite layer without reduction of the active material. The management of Si nanoantennas concentration provides a power conversion efficiency higher than 21% by increasing all main device parameters. The new silicon nanoparticles provide physical understanding on […]
Outstanding organic solar cells’ performance achieved by using new technology
EurekAlert June 23, 2021 Although the organic photovoltaic (OPV) elements are lighter, more flexible, and cheaper to produce, their efficiency still falls behind that of other photovoltaic technologies. An international team of researchers (Saudi Arabia, Lithuania, Greece) synthesised a material, which self-assembles into a monolayer that can cover a variety of surfaces and function as a hole-transporting layer in a solar element. They made some modifications in the material used in self-assembling molecular-thin layer (SAM) formation to tailor it for organic solar elements. The organic solar cell using Br-2PACz molecule-thin coating as a hole-transporting layer achieved a power conversion efficiency […]
Researchers make breakthrough in solar cell materials
Phys.org March 12, 2021 An international team of researchers (USA – Clemson University, Los Alamos National Laboratory, University of Alabama, China) observed the ultrafast dynamics of trapped carriers in organic methyl ammonium lead halide perovskite thin films by ultrafast photocurrent spectroscopy. Upon ultrafast laser excitation, trapped carriers followed a phonon assisted tunneling mechanism and a hopping transport mechanism along ultra-shallow to shallow trap states ranging from 1.72–11.51 millielectronvolts. They validated the transport mechanisms by highlighting trap state dynamics, including trapping rates, de-trapping rates and trap properties, such as trap density, trap levels, and capture-cross sections. The work establishes a foundation […]
New research could boost a solar-powered fuel made by splitting water
Science Daily March 10, 2021 Altering crystal facets exposed on the surface of photoelectrodes used for solar fuel production has been a major strategy for optimizing their properties. There are numerous ways to terminate the surface even for the same facet, which can considerably alter the photoelectrode properties. A team of researchers in the US (University of Wisconsin, University of Chicago, Brookhaven National Laboratory, Stony Brook University, Argonne National Laboratory) investigated using tightly integrated experimental and computational investigations of epitaxial BiVO4 photoelectrodes with vanadium- and bismuth-rich (010) facets. The study demonstrated that even for the same facet the surface Bi:V […]
Solar-powered system extracts drinkable water from ‘dry’ air
MIT News October 14, 2020 An international team of researchers (USA – MIT, University of Utah, South Korea) had developed a similar device as a proof of concept. The system, harnessed temperature difference within the device to allow an adsorbent material to draw in moisture from the air at night and release it the next day. The current work has demonstrated adsorption-based solar-thermal-driven atmospheric water harvesting (AWH) in arid regions, but the daily water productivity remained low. They developed and tested a dual-stage AWH device with optimized transport. By recovering the latent heat of condensation of the top stage and […]
Study offers new insights for sun-gathering technologies
Phys.org August 24, 2020 The direct integration of electrocatalysts with photovoltaic materials provides a strategy to photoelectrochemically power chemical transformations and store intermittent solar energy as fuels. Researchers at the Arizona State University highlight how optical and electrochemical characterization techniques can be coupled with structural information to address to what extent does a selected electrocatalytic coating screen photons from reaching the underlying photovoltaic; coating layers contribute to photocurrent production; and are relatively high or low loadings of catalytic sites advantageous. They used p-type gallium phosphide semiconductor that is interfaced with cobalt porphyrin hydrogen evolution reaction catalysts. Experimental techniques can likely […]
Efficient Off-Grid Power, After the Sun Sets
Optics and Photonics August 19, 2020 An international team of researchers (USA – Stanford, Israel) analyzed the basic thermodynamics of a heat engine, with the hot side under the roof and the top of the roof radiating thermal energy out into the environment. They developed models to maximize the amount of electrical power generated for various temperature gradients. The team’s design for a nighttime power generator would occupy a rooftop area of 1 m2. It incorporates a radiative emitting panel, a state-of-the-art TEG made of metal alloy, and a heat sink, with radiation shields and insulative pegs to reduce radiative […]