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An even better approximation of the temperature dependence of the resistivity of a semiconductor is given by the Steinhart–Hart equation: = + + (), where A, B and C are the so-called Steinhart–Hart coefficients. This equation is used to calibrate thermistors.
A temperature coefficient describes the relative change of a ... The increasing conductivity causes the resistivity of the semiconductor material to decrease with the ...
Near room temperature, the resistivity of metals typically increases as temperature is increased, while the resistivity of semiconductors typically decreases as temperature is increased. The resistivity of insulators and electrolytes may increase or decrease depending on the system. For the detailed behavior and explanation, see Electrical ...
The transistor's manufacturer will specify parameters in the datasheet called the absolute thermal resistance from junction to case (symbol: ), and the maximum allowable temperature of the semiconductor junction (symbol: ). The specification for the design should include a maximum temperature at which the circuit should function correctly.
The reciprocal of thermal conductivity is called thermal resistivity. The defining equation for thermal conductivity is q = − k ∇ T {\displaystyle \mathbf {q} =-k\nabla T} , where q {\displaystyle \mathbf {q} } is the heat flux , k {\displaystyle k} is the thermal conductivity, and ∇ T {\displaystyle \nabla T} is the temperature gradient .
With increasing temperature, phonon concentration increases and causes increased scattering. Thus lattice scattering lowers the carrier mobility more and more at higher temperature. Theoretical calculations reveal that the mobility in non-polar semiconductors, such as silicon and germanium, is dominated by acoustic phonon interaction.
The carrier density is important for semiconductors, where it is an important quantity for the process of chemical doping. Using band theory, the electron density, is number of electrons per unit volume in the conduction band. For holes, is the number of holes per unit volume in the valence band.
The corresponding resistivity of graphene sheets would be 10 −6 Ω⋅cm. This is less than the resistivity of silver, the lowest otherwise known at room temperature. [15] However, on SiO 2 substrates, scattering of electrons by optical phonons of the substrate is a larger effect than scattering by graphene's own phonons.