Category Physics

Match-Heads Boost Photovoltaic Efficiency

(Left) Silicon wires with match heads and (right) light absorption profile of a single match-head wire at 587 nm absorption. Credit: Image courtesy of the Center for Integrated Nanotechnologies

(Left) Silicon wires with match heads and (right) light absorption profile of a single match-head wire at 587 nm absorption. Credit: Image courtesy of the Center for Integrated Nanotechnologies

Crystal growth on a nano/microscale level produces “match-head”-like, 3D structures that enhance light absorption and photovoltaic efficiency. This is the first large structure grown on a nanowire tip and it creates a completely new architecture for harnessing energy. Match-head semiconductor nanowires focus incident light for greater overall efficiency. The match heads are naturally formed during the wire-growth process, which can be applied to various materials and structures for photonic and optoelectronic devices.

Enhanced light absorption and efficient, photogenerated carrier collection are...

Read More

DNA-Based Electromechanical Switch Demonstrated

The A-form of DNA between two electrodes. Credit: Image courtesy of University of California - Davis

The A-form of DNA between two electrodes. Credit: Image courtesy of University of California – Davis

Conductance of DNA can be modulated by controlling its structure, thus opening up the possibility of DNA’s future use as an electromechanical switch for nanoscale computing. Although DNA is commonly known for its biological role as the molecule of life, it has recently garnered significant interest for use as a nanoscale material for a wide-variety of applications.

Changing the structure of the DNA double helix by modifying its environment allows the conductance to be reversibly controlled. This ability to structurally modulate the charge transport properties may enable the design of unique nanodevices based on DNA...

Read More

A new ‘Periodic Table’ provides a unified way to classify and visualize Protein Complexes

Periodic Table of Protein Complexes | EMBL-EBI

The study provides insights into evolutionary distribution of different types of existing protein complexes. The table provides a valuable tool for biotechnology and the engineering of novel complexes.

Almost every biological process depends on proteins interacting and assembling into complexes in a specific way, and many diseases are associated with problems in complex assembly. The principles underpinning this organisation are not yet fully understood, but by defining the fundamental steps in the evolution of protein complexes, the new ‘periodic table’ presents a systematic, ordered view on protein assembly, providing a visual tool for understanding biological function.

“Evolution has given rise to a huge variety of protein complexes, and it can seem a bit chaotic,” explains Joe Marsh...

Read More

Heat Radiates 10,000 times Faster at the Nanoscale

The view inside the Ultra High Vacuum Scanning Thermal Microscope, which was used to measure temperature fluxes at the nanoscale. Credit: Joseph Xu

The view inside the Ultra High Vacuum Scanning Thermal Microscope, which was used to measure temperature fluxes at the nanoscale. Credit: Joseph Xu

When heat travels between 2 objects that aren’t touching, it flows differently at the smallest scales – distances on the order of the diameter of DNA, or 1/50,000 of a human hair. While researchers have been aware of this for decades, they haven’t understood the process. Heat flow often needs to be prevented or harnessed and the lack of an accurate way to predict it represents a bottleneck in nanotechnology development.

Now, in a unique ultra-low vibration lab at the University of Michigan, engineers have measured how heat radiates from one surface to another in a vacuum at distances down to 2nm...

Read More