Module 1: Part 1

1. Module 1: Part 1 Semiconductor Materials and Diodes

2. Learning Objectives • After studying this module, the reader should have the ability to: • Understand the concept of intrinsic carrier concentration, the difference between n-type and p-type materials, and the concept of drift and diffusion currents. • Analyze a simple diode circuit using the ideal diode current-voltage characteristics and using the iteration analysis technique. • Analyze a diode circuit using the piecewise linear approximation model for the diode. • Determine the small-signal characteristics of a diode using the small-signal equivalent circuit. • Understand the general characteristics of a solar cell, light-emitting diode, Schottky barrier diode, and Zener diode.

3. Ideal forward-biased I-V characteristics of pn junction diode, with the current plotted on a log scale for Is = 10-14 A and n = 1

4. The ideal diode: (a) I-V characteristics, (b) equivalent circuit under reverse bias, and (c) equivalent circuit in the conducting state

5. The diode rectifier: (a) circuit, (b) sinusoidal input signal, (c) equivalent circuit for vI> 0, (d) equivalent circuit for vI < 0, and (e) rectified output signal

6. The diode and load line characteristics for the circuit shown in Figure 1.24

7. The diode equivalent circuit (a) in the “on” condition when VD Vy, (b) in the “off” condition when VD < Vy, and (c) piecewise linear approximation when rf = 0

8. AC circuit analysis: (a) circuit with combined dc and sinusoidal input voltages, (b) sinusoidal diode current superimposed on the quiescent current, (c) sinusoidal diode voltage superimposed on the quiescent value, and (d) forward-biased diode I-V characteristics with a sinusoidal current and voltage superimposed on the quiescent values