The electronic and transport properties of electronic devices were reviewed in Chapter 1. These devices are usually microelectronic devices based on homojunction and heterojunction structures. Electronic devices are divided into two classes depending on their operational mode. The first class is called potential-effect devices, in which the transport properties are due to carrier injections. Bipolar transistors, which include heterojunction bipolar transistors (HBTs), and hot electron transistors (HETs) are examples of this class of devices. HETs include both ballistic injection devices and real-space transfer devices. The second class is called field-effect or voltage-controlled devices. Metal oxide–semiconductor field-effect transistors (MOSFETs), homogeneous field-effect transistors, and heterostructure field-effect devices all belong to the second class. There are several varieties of MOSFETs, such as semiconductor on insulator, complimentary MOSFETs, n-type MOSFETs, and p-type MOSFETs. Metal–semiconductor field-effect transistors (MESFETs) and junction field-effect transistors (JFETs) are examples of homogeneous field-effect devices. An example of heterojunctions field-effect devices is modulation-doped field-effect transistors (MODFETs), which are also called high electron mobility transistors (HEMTs). This chapter focuses on heterojunction devices, and thus, bipolar transistors and MOSFETs are not discussed, since they are the ...