The combination of inorganic and organic semiconductors promises hybrid functionality for optoelectronic and light-harvesting applications. Any functionality of such inorganic/organic hybrid system is governed by the electronic levels and resonances at the interface. These determine the efficiency of charge and energy transfer processes, which occur on ultrafast timescales (femto- to picoseconds) and compete with relaxation channels as polaron formation, decay to dark (triplet) states, or trapping at defect sites. Also the electronic structure of the inorganic semiconductor surface is vital for charge and energy transfer processes. Effects like surface band bending and surface photovoltage shifts can occur as well as the formation of thin charge accumulation layers with peculiar non-equilibrium properties.