Task: Text Categorization
Input (English): One section of these materials is known as the depletion zone. These materials are characterized by a small gap between the Fermi level and the valence band. Impurities are added to these materials in order to create either extra electrons or electron holes in the N- and P-types of these materials, respectively. That process is called (*) doping. These materials, such as germanium and gallium arsenide, are used in electronic devices such as diodes and transistors. For 10 points, name these materials, such as silicon, that have electrical conductivity in between that of a conductor and an insulator.
Output (English): Science