A quantum dot contains a small finite number (of the order of 1-100) of conduction band electrons, valence band holes, or excitons, i.e., a finite number of elementary electric charges.

For an electron to return from the conduction band to the valence band, it has to lose enough energy to cross the gap. It can make these transitions by absorbing or emitting a photon of light.

Given enough energy, electrons can be made to jump from the valence band into the conduction band in a semiconductor, and thus conduct electricity. Credit: Kelsey Casselbury Customizing the Gap: ...

Insights into atomic-scale defects may enable next-generation thin-film transistors for smartphones, televisions, and ...

When an electron drops from the conduction band to the valence band, it must lose that energy. In a light-emitting diode, electrons drop out of the conduction band by losing energy in the form of ...

Using optical excitation to create non-moving excitons—that is, excitons located at the minimum and maximum of the conduction band and valence band, respectively—is standard in insulators.

Another approach is to increase the switching rate. One way to do this is to use light rather than a transistor to control the flow of current – for example, by applying a laser pulse to excite the ...

When the wurtzite phase is sandwiched between the zincblende phase, the minimum of the conduction band and the maximum of the valence band are physically separated in the two different materials. Such ...