Photoexcitation

A research group led by Prof. Li Haiyang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has revealed a new competition mechanism in vacuum ultraviolet photoionization of dichloromethane using a home-built time-of-flight mass spectrometer (TOFMS).

The fine and efficient control of the properties of light at ultrafast speed down to the picosecond timescale is a challenging task, crucial for many scientific applications and technologies. For instance, in free-space optical links, manipulating on demand the attributes of light can be exploited to encode and transfer digital information robustly, over long distances and without optical fibers.

A new publication in Opto-Electronic Science reports how high-quality diamonds empower narrowband deep ultraviolet photodetection.

When designing optoelectronic devices, such as solar cells, photocatalysts, and photodetectors, scientists usually prioritize materials that are stable and possess tunable properties. This allows them precise control over optical characteristics of the materials and ensures retention of their properties over time, despite varying environmental conditions.

The quantum realm of atomic particles is embedded with randomness. Still, precise control of quantum systems, such as quantum computers, is of great importance for modern quantum science and prospective quantum technology.

At the heart of energy conversion, electrons and protons move in an intricate, coordinated dance. Chemists at Yale and in Sweden say they may have learned the steps to a new, photo-chemical rhumba.

A Quantum Dot (QD) is a nanometer-sized semiconductor nanocrystal that has unique optical properties such as the ability to emit light in the range of optical frequencies depending on its size. QDs have already been applied to practical optoelectronic applications including light-emitting displays, solar cells, photodetectors, and lasers.

Quantum Dot (QD) is a nanometer-sized semiconductor nanocrystal that has unique optical properties such as the ability to emit light in the range of optical frequencies depending on its size. QDs have already been applied to practical optoelectronic applications including light-emitting displays, solar cells, photodetectors, and lasers.

Excitons are electron-hole pairs in semiconductors that are electrostatically bound by strong Coulombic interactions. In ultrathin 2D semiconductors that are a few atoms thick (typically ~0.7 nm), the decreased z-dimension presents strong quantum confinement and reduced dielectric effects that feature a plethora of stable excitonic species (neutral excitons, trions, biexcitons, defect-bound excitons).

The bonds between clusters of elements in the fourteenth group of the periodic table are known to be fickle. Ranging from the nonmetal carbon, to the metalloids silicon and germanium, to the metals tin and lead, all these elements share the same configuration of valence electrons—electrons in their atoms' outermost energy level.

As semiconductor devices become ever smaller, researchers are exploring two-dimensional (2D) materials for potential applications in transistors and optoelectronics. Controlling the flow of electricity and heat through these materials is key to their functionality, but first we need to understand the details of those behaviors at atomic scales.

Single-molecule electronic devices, which use single molecules or molecular monolayers as their conductive channels, offer a new strategy to resolve the miniaturization and functionalization bottlenecks encountered by traditional semiconductor electronic devices. These devices have many inherent advantages, including adjustable electronic characteristics, ease of availability, functional diversity and so on.

Researchers at IMDEA Nanociencia have fabricated high quality microspheres from conjugated organic polymer blends with excellent lasing properties. The laser emission of the microspheres has the highest quality factor reported to date, Q>18,000.

Femtosecond transient microscopy is an important tool to study ultrafast transport properties of excited states in solid-state samples. Most implementations are limited to photoexciting a single diffraction-limited spot at the sample and tracking the temporal evolution of the ensuing carrier distribution, hence covering a very small sample area.

Electron-phonon scattering is often the primary mechanism limiting electron mobility in semiconductors. Thus, changing phonon properties can provide a way to control conductivity. Recently, there has been a growing interest in exploring the use of the quantum nature of light as an alternative approach. In this method, the material properties are modulated by tuning its interaction with the vacuum state of the…

The nucleobase molecules carrying the genetic codes are the most important ingredients for life, but they are also very vulnerable. When the ultraviolet component in the sunlight irradiates these molecules, the electrons in the molecules will be excited, and the excited nucleobase molecules may result in irreversible changes or even damages to the DNA and RNA chains, leading to the "sunburn" of organisms at…

In nature, the skin of cephalopods (animals with tentacles attached to the head) exhibits unparalleled camouflage ability. Their skin contains pigment groups that can sense changes in environmental light conditions, and they adjust their appearance through the action of pigment cells. Although intricate in nature, this color-changing ability is fundamentally based on a mechanical mechanism in which pigment…

Photoexcitation, and especially photoionization, is one of the most important manifestations of the light-matter interaction in nature, ranging from photosynthesis in plants and vision in biology to photography and laser processing of materials. It is generally accepted that the change in a substance is weaker the less light is absorbed. However, researchers found that this is not always the case.