: Semiconductors engineered via doping (adding intentional impurities) to drastically alter electrical properties:

Solid state physics dictates how carriers drift under electric fields and diffuse across concentration gradients. This physics underpins the operation of the , solar cells, light-emitting diodes (LEDs), and field-effect transistors (FETs). 6. Magnetic and Optical Properties

For a deep dive into electronic properties: Principles of Electronic Materials and Devices by S.O. Kasap.