Category Archives: Condensed matter

Silicon surfaces of crystalline solids are part of conventional electronics, but their exploitation in novel materials combining two-dimensional electron states (2DESs) and magnetism, which play an important role in the development of next-generation electronics, still remains elusive. The appearance of […]

Amplifying Voltage
If we place a large resistor in a circuit containing a transistor we can amplify the incoming voltage, since according to Ohm’s law voltage is equal to current times resistance. So a current crossing a small resistance corresponds […]

Nanoparticles of certain metals, like gold or silver, have attracted substantial interest in recent years owing to their ability to support localized surface plasmon resonances (collective oscillations of conduction electrons). These plasmonic excitations allow manipulation of light at the […]

The properties of n-type and p-type semiconductors were well known by the end of World War II, during which considerable research was devoted to electronics and the invention of radar. In 1947 three researchers at Bell Laboratories in New […]

A phase may be defined as a homogeneous portion of a system that has uniform physical and chemical characteristics. Every pure material is considered to be a phase; so also is every solid, liquid, and gaseous solution. For example, a […]

We saw that one of the devices based on semiconductors are photocells. A photocell working in reverse is also useful. If a conduction electron in an n-p diode happens to fall into a hole, it will emit the excess energy […]

A new vista in spintronics was opened in 2004 with the observation of the spin Hall effect in GeAs at 20 K by David Awschlom and his group. In the spin Hall effect the electrons of a charge current flow […]

Let’s take a p-type semiconductor with a very clean surface and place it right next to the clean surface of a n-type semiconductor. This type of device is called an n-p junction diode, or simply a diode. […]

Ionization is a fundamental process in chemistry and physics, lying at the heart of many fascinating phenomena.
Ionization is the process of producing ions. Certain molecules ionize in solution, for example. But ions may also be formed when an atom […]

The most extensive use of semiconductors, such as silicon or germanium, including their use as transistors, arises from their behavior when, after being sufficiently purified of atoms other than the basic element (e.g., silicon or germanium), very small amounts […]