zhterran said:We know in silicon a valence electron can be excited to conduction band if it absorbs one photon(one photon absorption) or two photon(two photon absorption),my question is that it must need a certain amount of time for the electron to 'travel' from the valence band to the conduction band(I cannot imagin a instantaneously transition with zero time),then how long is that time?
Valence electrons can become excited when they absorb energy from an external source, such as heat, light, or an electrical current. This causes them to jump to a higher energy level, known as the conduction band.
The time it takes for a valence electron to become excited and reach the conduction band can be influenced by several factors, including the energy of the external source, the type of material the electron is in, and any obstacles or barriers the electron may encounter.
No, the time it takes for a valence electron to become excited and reach the conduction band can vary depending on the type of material. For example, metals tend to have a shorter time due to their low resistance to electron flow, while insulators have a longer time due to their high resistance.
Yes, the time it takes for a valence electron to become excited and reach the conduction band can be measured using various techniques, such as spectroscopy, time-resolved microscopy, and ultrafast laser spectroscopy. These methods allow scientists to study the movement of electrons in real-time.
Understanding the time it takes for a valence electron to become excited and reach the conduction band is crucial in many fields of research, such as materials science, optoelectronics, and semiconductor technology. It allows scientists to design and develop new materials and devices with specific properties, such as faster electronic conductivity or higher energy efficiency.