Question

The diode current equation is

• A. \[ I_0\left(e^{\frac{V}{\eta V_T}}-1\right) \]
• B. \[ I_0e^{-\frac{V}{\eta V_T}} \]
• C. \[ I_0\left(e^{-\frac{V}{\eta V_T}}+1\right) \]
• D. \(I\)

Hint:

Remember the Shockley equation: \[ I=I_0 \left( e^{\frac{V}{\eta V_T}} - 1 \right) \] It is one of the most important equations in semiconductor electronics.

Answer 1

The Correct Option is A

Concept: The current flowing through a p-n junction diode is governed by the Shockley diode equation. This equation relates diode current to the applied voltage.

Step 1: Write the Shockley diode equation.
\[ I = I_0 \left( e^{\frac{V}{\eta V_T}} - 1 \right) \] where \[ I_0 = \text{Reverse saturation current} \] \[ V_T = \text{Thermal voltage} \] \[ \eta = \text{Ideality factor}. \]

Step 2: Interpret the equation.
For forward bias, \[ V>0, \] the exponential term becomes dominant and the diode current increases rapidly. For reverse bias, \[ V<0, \] the current approaches the reverse saturation current.

Step 3: Compare with options.
The standard diode current equation exactly matches \[ \boxed{ I_0 \left( e^{\frac{V}{\eta V_T}} - 1 \right) } \] Hence option (A) is correct.