Henryk said:No. Metal are substances which have partially filled conduction bands with electrons and the number of electrons is very high, one or two per atom.
Photoconductivity is observed mostly in semiconductors. Semiconductors have empty conduction band and almost full valence band just around 1 eV below.
The electrons in the conduction band are coming from either doping or are thermally excited and their number is rather small, one per millions of atoms.
When you shine light on a semiconductor you excite electrons from the valence to conduction band and the conductivity increases.
The effect of visible light on conductivity can vary depending on the material being studied. In some cases, visible light can increase conductivity by exciting electrons and promoting their movement. In other cases, visible light can decrease conductivity by creating electron-hole pairs that inhibit the flow of current.
The wavelength of visible light can have a significant impact on conductivity. In general, shorter wavelengths (such as blue or violet light) have a higher energy and can promote conductivity more effectively than longer wavelengths (such as red or green light).
Yes, visible light can be used to control conductivity in certain materials. This is known as photoconductivity and is often utilized in devices such as solar cells. By adjusting the intensity and wavelength of visible light, conductivity can be controlled and manipulated.
Materials that have a high number of free electrons are typically the most affected by visible light in terms of conductivity. This includes metals and some semiconductors. Insulators, on the other hand, are not as affected by visible light and have low conductivity even when exposed to light.
Yes, there are many practical applications of this phenomenon. As mentioned before, photoconductivity is used in solar cells to convert light energy into electrical energy. It is also utilized in devices such as photodetectors, optical switches, and even in optogenetics - a technique used to control cells with light.