Science Daily April 29, 2020 Inherently soft crystal lattice of Halide perovskites allows greater tolerance to lattice mismatch, making them promising for heterostructure formation and semiconductor integration. However, their high intrinsic ion mobility, which leads to interdiffusion and large junction widths and their poor chemical stability, epitaxial growth of atomically sharp heterostructures of halide perovskites has not yet been achieved. An international team of researchers (USA – Perdue University, MIT, UC Berkeley, Lawrence Berkeley National Laboratory, China) has developed a strategy to substantially inhibit in-plane ion diffusion in two-dimensional halide perovskites by incorporating rigid π-conjugated organic ligands. They have demonstrated […]
Tag Archives: Solar energy
After 40 Years of Hunting, Scientists Identify a Key Flaw in Solar Panel Efficiency
Science Alert February 13, 2020 Silicon solar cells containing boron and oxygen suffer from Light Induced Degradation which could be responsible for the 2 percent efficiency drop that solar cells can see in the first hours of use. Using deep level transient spectroscopy and photoluminescence an international team of researchers (UK, Portugal, Belarus, Australia) has observed the conversion of a deep boron-di-oxygen-related donor state into a shallow acceptor which correlates with the change in the lifetime of minority carriers in the silicon. They propose structures of the BsO2 defect which match the experimental findings and hypothesize that the dominant recombination […]
Anti-solar cells: A photovoltaic cell that works at night
Science Daily January 29, 2020 Photovoltaics can generate electricity during daylight hours. Researchers at the University of Maryland consider an alternative photovoltaic concept that uses the earth as a heat source and the night sky as a heat sink, resulting in a “nighttime photovoltaic cell” that employs thermoradiative photovoltaics and concepts from the advancing field of radiative cooling. In this perspective, they discuss the principles of thermoradiative photovoltaics, the theoretical limits of applying this concept to coupling with deep space, the potential of advanced radiative cooling techniques to enhance their performance, and a discussion of the practical limits, scalability, and […]
Tweaks behind the rebirth of nearly discarded organic solar technologies
Science Daily December 19, 2019 Unlike silicon solar technology, non-fullerene acceptors (NFAs) can be shaped, made semi-transparent or colored and fine-tuned to free up and move electrons to generate electricity. Researchers at Georgia Institute of Technology have modeled tiny tweaks to molecular shapes and calculated corresponding energy conversion in a common NFA electron donor/acceptor pairing. Improved performance came from tweaks to a tiny component, a methoxy group, on the acceptor, and two positions out of four possible positions it took boosted the conversion of light into electricity from 6% to 12%…read more. Open Access TECHNICAL ARTICLE
Daylight damage to photovoltaics
Science Daily December 2, 2019 The cumulative damage from the sun tends to erode efficiency of a new class of solar cells that utilizes layers of carbon-based polymers. Based on the results of current-voltage curves, impedance spectroscopy, and UV-VIS spectrophotometry, researchers in Japan have determined that exposure to the sun’s ultraviolet light can damage the fragile organic molecules in the semiconducting layer just like it damages human skin. When some sulfur atoms in the materials get replaced by oxygen atoms from the atmosphere, the molecules no longer function as intended. The degradation products from solar damage increased the electrical resistance […]
Converting absorbed photons into twice as many excitons
Science Daily September 24, 2019 An international team of researchers (Japan, Finland) found that when light was exposed to the surface of a tetracene alkanethiol-modified gold nanocluster, they were able to convert singlet oxygen at a highly efficient conversion rate of 160%, far exceeding 100% conversion, in comparison to the number of absorbed photons. An increase in lifetime of about 10,000 times was achieved by greatly suppressing the rapid loss of excitation energy on the metal surface. These findings are expected to contribute to areas such as solar energy conversion, electronics, life sciences, and medical care in the future…read more. […]
After 40 Years of Searching, Scientists Identify The Key Flaw in Solar Panel Efficiency
Science Alert June 8, 2019 Silicon solar cells containing boron and oxygen are one of the most rapidly growing forms of electricity generation. However, they suffer from significant degradation during the initial stages of use. Using ab initio modeling, an international team of researchers (UK, Portugal, Belarus, Australia) proposes structures of the BsO2 defect which match the experimental findings. They argue that the dominant recombination process associated with degradation is trap-assisted Auger recombination. This assignment is supported by the observation of above bandgap luminescence due to hot carriers resulting from the Auger process…read more. Open Access TECHNICAL ARTICLE
Using DNA templates to harness the sun’s energy
Science Daily April 25, 2019 A team of researchers in the US (Arizona State University, University of New Mexico) reports significant progress in optimizing systems that mimic the first stage of photosynthesis. In previous the team demonstrated the utility of DNA to serve as a programmable template for aggregating dyes. To build upon these findings, they will use the photonic principles that underlie natural light harvesting complexes to construct programmable structures based on DNA self-assembly, which provides the flexible platform necessary for the design and development of complex molecular photonic systems. Using DNA architectures as a template, the researchers were able […]
Mystery of negative capacitance in perovskite solar cells solved
Eurekalert April 5, 2019 An international team of researchers (Switzerland, Iran) found that the large perovskite capacitances are not classical capacitances in the sense of charge storage, but just appear as capacitances because of the cells’ slow response time. They found that the origin of the apparent capacitance is a slow modification of the current passing the contact of the solar cells, which is regulated by a slow accumulation of mobile ionic charge. A slowly increasing current appears like a negative capacitance in the impedance spectra. The work sheds light on the interaction between the photovoltaic effect in these devices […]
China Stumbles on Path to Solar Thermal Supremacy
IEEE Spectrum February 14, 2019 Solar thermal plants are a potentially crucial power source for global grids as they add more wind and PV. However, the technology is comparatively costly and thus growing slowly relative to PV and wind. China’s program has been viewed as an opportunity to put solar thermal technology back on track, slash the cost of solar thermal power and catapult Chinese firms to the head of the global pack. In the final days of 2018 a 100-megawatt solar thermal generating station capable of running around-the-clock, 365-days-a-year was to be connected to the Northwest China regional power […]