For a semiconductor to manipulate electricity in a device, two requirements must be met:

• There should be an imbalance of electrons across the semiconductor (areas of high and low electron density)
• Under certain conditions e.g., applied heat or light, electrons should be able to move freely throughout the semiconductor.

There are different ways charge can be conducted through a semiconductor. The mechanism is dependent on the material itself. Typical semiconducting materials, such as silicon, are solid state lattices of one element that can be modified to incorporate different atoms. Charge flows through the crystalline lattice of that material with different atoms incorporating more of a particular type of charge carrier (electron or hole).

Other materials such as small organic molecule do not form lattices. Charge flows within the molecule and also hops between molecules. Whilst this might limit conductivity to some extent these materials offer more opportunities within an electronic device that traditional inorganic semiconductor materials can not.