valence band

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electron transition

valence band

physics

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electron transition — electron transition Figure 2: Transition of an electron from the valence band to the conduction band by light absorption (see text).

In physics, the valence band refers to the range of the highest energies that electrons can possess while remaining associated with a specific atom in a solid material. These are the outermost electrons, known as valence electrons, which are involved in forming chemical bonds and conducting electricity in metals and semiconductors.12

According to band theory, electrons in solids can only have energies within specific allowed ranges, called bands. The valence band is one such allowed band, formed when atoms come together to create a solid, perturbing their individual energy levels. Above the valence band is typically an empty band called the conduction band, separated by a forbidden energy gap. The behavior of electrons in these bands determines whether a material acts as a metal, insulator, or semiconductor.3

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colour
Pure semiconductors
…full lower band, called the valence band, and an exactly empty upper band, the conduction band. Because there are no electron energy levels in the gap between the two bands, the lowest energy light that can be absorbed corresponds to arrow A in the figure; this represents the excitation of…
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…full lower band, called the valence band, and an exactly empty upper band, the conduction band. Because there are no electron energy levels in the gap between the two bands, the lowest energy light that can be absorbed corresponds to arrow A in the figure; this represents the excitation of…
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electricity
Conductors, insulators, and semiconductors
…by electrons is the valence band. In a conductor, the valence band is partially filled, and since there are numerous empty levels, the electrons are free to move under the influence of an electric field; thus, in a metal the valence band is also the conduction band. In an insulator,…
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…by electrons is the valence band. In a conductor, the valence band is partially filled, and since there are numerous empty levels, the electrons are free to move under the influence of an electric field; thus, in a metal the valence band is also the conduction band. In an insulator,…
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industrial glass
Electronic conduction
…specific energy levels known as valence and conduction bands. As the temperature is raised, some electrons from the valence band are able to jump across to the conduction band, thus contributing to what is known as the intrinsic conductivity of the atom. In extrinsic semiconductivity, on the other hand, electrons…
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…specific energy levels known as valence and conduction bands. As the temperature is raised, some electrons from the valence band are able to jump across to the conduction band, thus contributing to what is known as the intrinsic conductivity of the atom. In extrinsic semiconductivity, on the other hand, electrons…
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luminescence
Mechanism of luminescence
…to be found on the valence band, whereas they reach the conduction band after sufficient excitation. The energy difference between the valence band and the conduction band corresponds to photons in the ultraviolet or still shorter wavelength region. Additional energy levels are introduced by activator ions or centres bridging the…
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…to be found on the valence band, whereas they reach the conduction band after sufficient excitation. The energy difference between the valence band and the conduction band corresponds to photons in the ultraviolet or still shorter wavelength region. Additional energy levels are introduced by activator ions or centres bridging the…
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photoelectric effect
Photoelectric principles
…material is known as the valence band, and the degree to which it is filled largely determines the material’s electrical conductivity. In a typical conductor (metal), the valence band is about half filled with electrons, which readily move from atom to atom, carrying a current. In a good insulator, such…
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…material is known as the valence band, and the degree to which it is filled largely determines the material’s electrical conductivity. In a typical conductor (metal), the valence band is about half filled with electrons, which readily move from atom to atom, carrying a current. In a good insulator, such…
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materials science
Photovoltaics
…to jump from the lower-energy valence band to the higher-energy conduction band. The electrons in the conduction band and the holes they have left behind in the valence band are both mobile and can be induced to move by a voltage. The electron motion, and the movement of holes in…
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…to jump from the lower-energy valence band to the higher-energy conduction band. The electrons in the conduction band and the holes they have left behind in the valence band are both mobile and can be induced to move by a voltage. The electron motion, and the movement of holes in…
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