Analysis in equilibrium:

Solution of Poisson's Equation with suitable boundary conditions - Non-equilibrium analysis:

1. The electron and hole densities are no longer linked together through the inverse relationship of Eq. (5) but by complex relationships involving all three variables Y , , p
2. The three variables are generally independent of each other in the sense that knowledge of two of them does not direct automatically to knowledge of the third.
3. The idea of Fermi energy is no longer valid but new quantities termed as the quasi-Fermi levels are employed and these are not in general constant.
4. For static or dc analysis, the continuity equation turns into time independent so that only ordinary differential equations require to be solved.
5. For dynamic analysis though, the partial differential equations have to be solved increasing the complexity of the analysis.