Solid State Electronic Devices, 7th Edition

7.1 Fundamentals of BJT Operation

The bipolar transistor is basically a simple device, and this section is devoted to a simple and largely qualitative view of BJT operation. We will deal with the details of these transistors in the following sections, but first we must define some terms and gain physical understanding of how carriers are transported through the device. Then we can discuss how the current through two terminals can be controlled by small changes in the current at a third terminal.

Let us begin the discussion of bipolar transistors by considering the reverse-biased p-n junction diode of Fig. 7–1. According to the theory of Chapter 5, the reverse saturation current through this diode depends on the rate at which minority carriers ...