electromagnetism

P-N Junction

Explore the fundamental building block of diodes, transistors, solar cells, and LEDs. See the 3D semiconductor crystal lattice, depletion region, and how biasing affects current flow.

P-N Junction

A-Level

A P-N junction forms when p-type and n-type semiconductors are joined. Electrons and holes diffuse across the junction, creating a depletion region. Forward bias narrows the depletion region allowing current; reverse bias widens it.

Bias Voltage0.5V

Doping Level5arb.

📐 Formulas

I = I_s(e^{V/nV_T} - 1)Current-voltage characteristic

V_T = \frac{kT}{e} \approx 26\,\text{mV}At room temperature

📋 Syllabus

AQA3.13.3