Band Bending in Semiconductors: Chemical and Physical Consequences at Surfaces and Interfaces

A study was conducted to investigate the chemical and physical consequences at surfaces and interfaces of band bending in semiconductors. The study focused on the principles of band bending and its effect on photochemistry and photocatalysis. The energy band edges in the semiconductor were shifted continuously in the space charge region due to the electric field between the semiconductor and the metal due to the charge transfer, which was called band bending. The unpaired electrons in the dangling bonds of surface atoms interacted with each other forming an electronic state with a narrow energy band at the semiconductor band gap. The Fermi level of the bulk was also located at the midgap and was equal in energy to the surface Fermi level when the semiconductor was undoped.