PN junction current equation

[wrong_class]

What are e and V in exponent of the equation I = I₀(e^eV/kT - 1)? is it really one variable "eV", as in electron volts, or is e just 2.718... and V for volts?

 

[marcusl]

Two; e is the charge on an electron, V is the potential.

 

[phyzguy]

It's confusing. The first e is just the base of the natural logarithms (2.718...), but the e in the exponent is the charge on the electron. I prefer to write it as:
$$e^\frac{qV}{kT}$$ to eliminate this confusion. Note that if you measure kT in electron volts (eV), then the electron charges cancel, and you can just use the voltage V directly. Note that at room temperature, kT is .026 eV, so you can write:
$$I = I_0 e^\frac{V}{.026}$$

 

[wrong_class]

Thanks!

 

[paranormal]

The PN junction current equation is a fundamental equation in semiconductor physics that describes the current flowing through a PN junction under different bias conditions. In this equation, I represents the current, I0 is the reverse saturation current, e is the elementary charge, V is the voltage across the junction, k is the Boltzmann constant, and T is the temperature.

The term "e" in the exponent is indeed the mathematical constant 2.718, also known as Euler's number. This constant is commonly used in exponential functions and is an important value in many areas of mathematics and science.

The term "V" in the exponent represents the voltage across the PN junction, measured in volts. This is a key variable in the equation as it determines the strength of the electric field across the junction, which in turn affects the flow of current.

It is important to note that the units for "e" and "V" are different, with "e" being dimensionless and "V" having units of volts. This can sometimes lead to confusion, but it is important to remember that they are separate variables in the equation.

In summary, the PN junction current equation incorporates a number of important variables, including the elementary charge, voltage, and temperature, to describe the behavior of current in a PN junction. It is a crucial equation in semiconductor physics and is used extensively in the design and analysis of electronic devices.