Bandgap

The bandgap is the difference between the maximum energy point in the valence band and the minimum point in the conduction band. ❋ Unknown (2009)

The indirect bandgap occurs when the maximum valence point and minimum conduction point are not aligned on the same wave vector. ❋ Unknown (2009)

"Graphene doesn't naturally have a bandgap, which is necessary for most electronic applications," said IBM Fellow Phaedon Avouris, who oversees the company's carbon-based materials efforts. ❋ Unknown (2010)

The direct bandgap occurs when these maximum and minimum points are aligned along the same wave vector. ❋ Unknown (2010)

The direct bandgap occurs when these maximum and minimum points are aligned along the same wave vector. [ ❋ Unknown (2009)

The bandgap of GaAs corresponds to wavelengths longer than 1 micron. ❋ Unknown (2010)

If silicon is alloyed with other materials like germanium, amorphous silicon could reach a lower, and thus more optimal, bandgap. ❋ Unknown (2009)

To excite an electron across a direct bandgap, the valence electron and a photon, bundles of a large amount of energy with a small amount of momentum that come from the sun, must have an energy and momentum equal to or greater than that of the empty conduction band state. ❋ Unknown (2009)

For the electron to cross an indirect bandgap, the photon alone will not provide the electron with the correct energy and momentum to land itself in the conduction band state. ❋ Unknown (2009)

The dyes absorb light with sub-bandgap energies, and can then inject excited electrons into the C.B. A fractal dye surface on TiO2 now holds the record for solar energy conversion to chemical energy (O'Regan & Graetzel, 1991). ❋ Unknown (2005)

Another efficiency -- i.e., practicality -- issue with wide-bandgap superconductors is that fact that only high-energy photons work. ❋ Unknown (2005)

If a photon has energy less than the bandgap, it's merely reflected or thermalized, which means it does no good at all. ❋ Unknown (2005)

Unfortunately, most also are "wide-bandgap" semiconductors, with bandgap energies about halfway between "regular" semiconductors and insulators. ❋ Unknown (2005)

First, it has a very high refractive index, and second, its bandgap width (and hence photon absorption cutoff) lies just beyond the visible, at a wavelength of about 390 nanometers. ❋ Unknown (2005)

From 1984 to 1989, he was a senior scientist at 3M Corporation, developing some of the first models for electronic transport and optical properties of wide bandgap II-VI semiconductors.

The ISL21090 is a wide input range, low noise precision bandgap voltage reference that provides half the noise of alternative solution with only half the power consumption.

The ISL21090 bandgap filter features output noise voltage of 1.9uV peak-peak over 0.1Hz to 10Hz with broadband noise voltage at 1.6uVrms, which en-genius.net editors noted is dramatically better than available elsewhere.

'But the way the cell is fabricated means we're not dependent on the bandgap energy like silicon solar cells. ❋ Unknown (2010)