Practice question

**Semiconductor properties** distinguish from conductors and insulators by temperature dependence and doping response. At 0 K intrinsic acts as insulator, conductivity due to thermally generated electron-hole pairs, number of outer electrons 4 for Si/Ge forming covalent bonds, each atom shares electrons, crystal with N atoms has 4N valence electrons, 2N bonds. The total current ( I ) in an intrinsic semiconductor is the sum of electron current ( I_e ) and hole current ( I_h ), i.e., I = I_e + I_h . Substituting values gives Electron and hole currents, which matches expected behaviour for this semiconductor device configuration, confirming doping, depletion and rectifier principles.