CBSE Class 12 Physics – Semiconductor Electronics: Materials, Devices, and Simple Circuits

Chapter Overview

This chapter delves into semiconductors—their materials, energy bands, and how doping creates p- and n-type types. You’ll learn about p-n junctions, diode characteristics, applications like rectifiers and voltage regulators, special-purpose diodes (LED, photodiode, Zener), BJTs, and simple transistor circuits. It also covers digital logic gates and circuit basics.

Important Keywords

• Semiconductor: Material with conductivity between conductors and insulators; conductivity tunable by doping. :contentReference[oaicite:0]{index=0}
• Intrinsic Semiconductor: Pure; charge carriers generated thermally.
• Extrinsic Semiconductor: Doped: n-type (electrons majority), p-type (holes majority). :contentReference[oaicite:1]{index=1}
• P–N Junction: Interface between p- and n-type; depletion region forms. :contentReference[oaicite:2]{index=2}
• Diode: Two-terminal device allowing current one way; forward/reverse I–V characteristics. :contentReference[oaicite:3]{index=3}
• Zener Diode: Special diode for voltage regulation in reverse bias.
• LED: Light-emitting diode; electroluminescence from electron–hole recombination. :contentReference[oaicite:4]{index=4}
• Photodiode: Generates current when illuminated; used in sensors. :contentReference[oaicite:5]{index=5}
• BJT: Bipolar Junction Transistor (n-p-n or p-n-p); current-controlled device for amplification.
• Logic Gates: Digital operations (AND, OR, NOT, NAND, NOR); built from transistors/diodes. :contentReference[oaicite:6]{index=6}