How do diodes work?

 Diodes are electronic components that allow current to flow in only one direction — like a one-way valve for electricity.

🔧 How a Diode Works (Basic Principle)

• A diode is made from a semiconductor material, usually silicon, and has two terminals:
• Anode (positive side)
• Cathode (negative side)
• The key structure of a diode is the PN junction:
• The P-type side has positive charge carriers (holes).
• The N-type side has negative charge carriers (electrons).
• When these materials are joined:
• A depletion region forms at the junction, which acts like a barrier to current flow.

🔁 Two Modes of Operation

1. Forward Bias (Current Flows)

• Positive voltage on the anode, negative on the cathode.
• The electric field reduces the depletion region, allowing current to flow.
• Electrons and holes recombine, enabling current movement across the junction.

✅ Result: Current flows freely.

2. Reverse Bias (No Current Flows)

• Negative voltage on the anode, positive on the cathode.
• The depletion region widens, blocking current.
• Only a tiny leakage current flows, almost negligible.

🚫 Result: No significant current flow.

🧩 What Are Diodes Used For?

• Rectification – converting AC to DC (used in power supplies)
• Protection – preventing reverse voltage damage
• Signal demodulation – extracting audio from radio signals
• Light emission – in LEDs (Light Emitting Diodes)