Semiconductor Electronics: Materials, Devices and Simple Circuits formulas

Formulas

Intrinsic semiconductor

$\displaystyle n_e = n_h = n_i$

Mass action law

$\displaystyle n_en_h = n_i^2$

Current in a semiconductor

$\displaystyle I = I_e + I_h$

Half-wave rectifier output

$\displaystyle \nu_{\text{out}} = \nu_{\text{in}}$

Full-wave rectifier output

$\displaystyle \nu_{\text{out}} = 2\nu_{\text{in}}$

Key facts

• n-type: doped with pentavalent atoms such as phosphorus, and electrons are the majority carriers.
• p-type: doped with trivalent atoms such as boron, and holes are the majority carriers.
• Both types stay electrically neutral overall.
• Forward bias narrows the depletion region and current flows. Reverse bias widens it, and only a tiny current flows.
• An insulator has a large band gap, a semiconductor a small one, and a conductor none or overlapping bands.