Physicochemistry of semiconductors

The purpose is to introduce electronic transport properties of organic and inorganic semiconductors as well as the basic principles of semiconductor-based devices. The course contents is the following: Part 1 – band structure of semiconductors (direct versus indirect bandgap), density of states, notion of hole, density of charge carriers, intrinsic and extrinsic semiconductors (doping and temperature effects); electronic transport (Drude model: conductivity, mobility of charge carriers), drift current under electric field versus diffusion current under gradient of concentration, polarizability (delocalized transport versus hoping), out-of-equilibrium semiconductor (generation/recombination processes of charge carriers). Part 2 – Inorganic PN junction (Schockley equation), organic Schottky diode (metal/organic semiconductor interface), optical properties of organic and inorganic semiconductors (light absorption, photoluminescence and electroluminescence), basic operation of  optoelectronic devices (photodiode, photovoltaic diode, electroluminescent diode. 

wave/particle duality; pi-conjugated system; cubic crystal lattice in direct and reciprocal space; electron diffraction by crystal lattice; free electron gas (Sommerfeld model: electron energy quantization, standing electronic waves in the crystal, periodic boundary conditions); wave function of electron in periodic potential (Bloch theorem); theory of energy bands (Fermi surface, Brillouin zones, bandgap, density of states of 1D, 2D, 3D crystals) ; perfect Fermi gas (Fermi-Dirac statistics).