UC Berkeley researchers just broke another record in photovoltaic efficiency, an achievement that could lead to an ultralight engine that can power drones for days.
For the past 15 years, the efficiency of converting heat into electricity with thermovoltaics has been stalled at 23 percent. But a groundbreaking physical insight has allowed researchers to raise this efficiency to 29 percent. Using a novel design, the researchers are now aiming to reach 50 percent efficiency in the near future by applying well-established scientific concepts.
A new measurement technique may finally dissolve doubts about the quality of quantum dots.
Quantum dots—tiny, easy-to-produce particles—may soon take the place of more expensive single crystal semiconductors in advanced electronics found in solar panels, camera sensors, and medical imaging tools.
Although quantum dots have begun to break into the consumer market—in the form of quantum dot TVs—long-standing uncertainties about their quality have hampered their adoption.
“Traditional semiconductors are single crystals, grown in vacuum under special conditions. These we...
The International Union of Pure and Applied Chemistry (IUPAC) has released the results of its first search for the Top Ten Emerging Technologies in Chemistry. Initiated as a special activity in honor of IUPAC’s 100th anniversary this year, the results have been published in the 2019 April-June 2019 issue of Chemistry International(link is external). Research from the lab of ...
Richard H. Friend, Felix Deschler, Luis M. Pazos-Outón, Mojtaba Abdi-Jalebi, Mejd Alsari | SciVPro
Interdigitated back-contact (IBC) architectures are the best performing technology in crystalline Si (c-Si) photovoltaics (PV). Although single junction perovskite solar cells have now surpassed 23% efficiency, most of the research has mainly focussed on planar and mesostructured architectures. The number of studies involving IBC devices is still limited and the proposed architectures are unfeasible for large scale manufacturing. Here we discuss the importance of IBC solar cells as a powerful tool for investigating the fundamental working mechanisms of perovskite materials. We show a...
Sulfated metal–organic framework-808 (S-MOF-808) exhibits strong Brønsted-acidic character which makes it a potential candidate for the heterogeneous acid catalysis. Here, we report the isomerization and oligomerization reactions of light olefins (C3–C6) over S-MOF-808 at relatively low temperatures and ambient pressure. Different products (dimers, isomers, and heavier oligomers) were obtained for different olefins, and effective C–C coupling was observed between isobutene and isopentene. Among the substrates investigated, facile oligomerization occurred very specifically for the...
We present a framework for simulating relaxation dynamics through a conical intersection of an open quantum system that combines methods to approximate the motion of degrees of freedom with disparate time and energy scales. In the vicinity of a conical intersection, a few degrees of freedom render the nuclear dynamics nonadiabatic with respect to the electronic degrees of freedom. We treat these strongly coupled modes by evolving their wavepacket dynamics in the absence of additional coupling exactly. The remaining weakly coupled nuclear degrees of freedom are partitioned into modes...
Lithium, a prototypical simple metal under ambient conditions, has a surprisingly rich phase diagram under pressure, taking up several structures with reduced symmetry, low coordination numbers, and even semiconducting character with increasing density. Using first-principles calculations, we demonstrate that some predicted high-pressure phases of elemental Li also host topological electronic structures. Beginning at 80 GPa and coincident with a transition to the previously predictedPbcaphase, we find Li to be a Dirac nodal line semimetal. We further calculate...
We present a simple nanopore-electroporation (NanoEP) platform for delivery of nucleic acids, functional protein, and Cas9 single-guide RNA ribonucleoproteins into both adherent and suspension cells with up to 80% delivery efficiency and >95% cell viability. Low-voltage electric pulses permeabilize a small area of cell membrane as a cell comes into close contact with the nanopores. The biomolecule cargo is then electrophoretically drawn into the cells through the nanopores. In addition to high-performance delivery with low cell toxicity, the NanoEP system does not require...
We present a strategy for mapping the dynamics of a fermionic quantum system to a set of classical dynamical variables. The approach is based on imposing the correspondence relation between the commutator and the Poisson bracket, preserving Heisenberg's equation of motion for one-body operators. In order to accommodate the effect of two-body terms, we further impose quantization on the spin-dependent occupation numbers in the classical equations of motion, with a parameter that is determined self-consistently. Expectation values for observables are taken with respect to an initial...
