p-n Junction Diode

• Basic device technology

• Structure and principle of operation

• Electrostatic analysis of a p-n diode

– Depletion region and depletion capacitance

– Abrupt junction

– Linearly graded junction

• Current - voltage characteristics

– Shockley equation

– Generation-Recombination Process

– High injection

– Diffusion capacitance

• Reverse bias breakdown

– Thermal instability

– Tunneling effect

– Avalanche multiplication

• Transient behavior

Structure and principle of operation

Energy band diagram of a p-n junction (a) before and (b) after merging the n-type and p-type regions

Thermal equilibrium

Energy band diagram of a p-n junction under reverse and forward bias

General discussion - Poisson's equation

Não é trivial de resolver!

The full-depletion approximation

• 1. Região de carga espacial

• 2. Nível de Fermi em equilíbrio

• 3. Built-in voltage

• 4. Built-in voltage e densidade de dopantes

• 5. Largura da região de carga espacial

• 6. Capacitância de depleção

The linearly graded p-n junction

The p-n diode current

The ideal diode current

p-n Junction Diode

Exemplos e Exercícios