Band bendingIn solid-state physics, band bending refers to the process in which the electronic band structure in a material curves up or down near a junction or interface. It does not involve any physical (spatial) bending. When the electrochemical potential of the free charge carriers around an interface of a semiconductor is dissimilar, charge carriers are transferred between the two materials until an equilibrium state is reached whereby the potential difference vanishes.
Greatest GenerationThe Greatest Generation, also known as the G.I. Generation and the World War II generation, is the Western demographic cohort following the Lost Generation and preceding the Silent Generation. The generation is generally defined as people born from 1901 to 1927. They were shaped by the Great Depression and were the primary generation composing the enlisted forces in World War II. Most people of the Greatest Generation are the parents of the Silent Generation and Baby Boomers, and, in turn, were the children of the Lost Generation.
Generation ZGeneration Z (often shortened to Gen Z), colloquially known as zoomers, is the demographic cohort succeeding Millennials and preceding Generation Alpha. Researchers and popular media use the mid-to-late 1990s as starting birth years and the early 2010s as ending birth years. Most members of Generation Z are children of Generation X or younger Baby Boomers. The older members may be the parents of the younger members of Generation Alpha.
Silent GenerationThe Silent Generation, also known as the Traditionalist Generation, is the Western demographic cohort following the Greatest Generation and preceding the baby boomers. The generation is generally defined as people born from 1928 to 1945. By this definition and U.S. Census data, there were 23 million Silents in the United States as of 2019. In the United States, the Great Depression of the 1930s and World War II in the early-to-mid 1940s caused people to have fewer children and as a result, the generation is comparatively small.
Semiconductor deviceA semiconductor device is an electronic component that relies on the electronic properties of a semiconductor material (primarily silicon, germanium, and gallium arsenide, as well as organic semiconductors) for its function. Its conductivity lies between conductors and insulators. Semiconductor devices have replaced vacuum tubes in most applications. They conduct electric current in the solid state, rather than as free electrons across a vacuum (typically liberated by thermionic emission) or as free electrons and ions through an ionized gas.
Photovoltaic effectThe photovoltaic effect is the generation of voltage and electric current in a material upon exposure to light. It is a physical and chemical phenomenon. The photovoltaic effect is closely related to the photoelectric effect. For both phenomena, light is absorbed, causing excitation of an electron or other charge carrier to a higher-energy state. The main distinction is that the term photoelectric effect is now usually used when the electron is ejected out of the material (usually into a vacuum) and photovoltaic effect used when the excited charge carrier is still contained within the material.
Building-integrated photovoltaicsBuilding-integrated photovoltaics (BIPV) are photovoltaic materials that are used to replace conventional building materials in parts of the building envelope such as the roof, skylights, or facades. They are increasingly being incorporated into the construction of new buildings as a principal or ancillary source of electrical power, although existing buildings may be retrofitted with similar technology.
Fermi energyThe Fermi energy is a concept in quantum mechanics usually referring to the energy difference between the highest and lowest occupied single-particle states in a quantum system of non-interacting fermions at absolute zero temperature. In a Fermi gas, the lowest occupied state is taken to have zero kinetic energy, whereas in a metal, the lowest occupied state is typically taken to mean the bottom of the conduction band. The term "Fermi energy" is often used to refer to a different yet closely related concept, the Fermi level (also called electrochemical potential).
Photovoltaic power stationA photovoltaic power station, also known as a solar park, solar farm, or solar power plant, is a large-scale grid-connected photovoltaic power system (PV system) designed for the supply of merchant power. They are different from most building-mounted and other decentralized solar power because they supply power at the utility level, rather than to a local user or users. Utility-scale solar is sometimes used to describe this type of project.
Photovoltaic system performancePhotovoltaic system performance is a function of the climatic conditions, the equipment used and the system configuration. PV performance can be measured as the ratio of actual solar PV system output vs expected values, the measurement being essential for proper solar PV facility's operation and maintenance. The primary energy input is the global light irradiance in the plane of the solar arrays, and this in turn is a combination of the direct and the diffuse radiation.
Valence and conduction bandsIn solid-state physics, the valence band and conduction band are the bands closest to the Fermi level, and thus determine the electrical conductivity of the solid. In nonmetals, the valence band is the highest range of electron energies in which electrons are normally present at absolute zero temperature, while the conduction band is the lowest range of vacant electronic states. On a graph of the electronic band structure of a semiconducting material, the valence band is located below the Fermi level, while the conduction band is located above it.
Generation XGeneration X (often shortened to Gen X) is the demographic cohort following the baby boomers and preceding the millennials. Researchers and popular media use the mid-to-late 1960s as starting birth years and the late 1970s to early 1980s as ending birth years, with the generation being generally defined as people born from 1965 to 1980. By this definition and U.S. Census data, there are 65.2 million Gen Xers in the United States as of 2019.
