Utilizing organic materials for eco-friendly devices.

Unlike inorganic crystals where doping introduces free electrons or holes, organic semiconductors host charges as polarons . Adding an electron to a chain distorts the local molecular geometry, and the combined entity (charge + lattice distortion) is called a polaron. Similarly, removing an electron creates a positive polaron (hole). These polarons hop between molecules or along polymer chains—a process described by hopping transport , not band-like motion.

Common in organics, these are tightly bound to a single molecule.

In inorganic semiconductors, atomic orbitals merge to form valence and conduction bands. In organic molecules, the overlapping orbitals form discrete molecular orbitals:

Low-molecular-weight materials (e.g., pentacene, rubrene, fullerene derivatives like PCBM) that are typically deposited via vacuum thermal evaporation or specialized solution processing.