Because organic films are often amorphous or polycrystalline, charges don't flow smoothly. Instead, they "hop" from one localized molecular site to another. This process is thermally activated; as temperature rises, conductivity typically increases—the opposite of most metals.
Instead of valence and conduction bands, organic molecules feature discrete molecular orbitals:
Understanding the Physics of Organic Semiconductors Organic semiconductors have revolutionized modern electronics by enabling flexible displays, lightweight solar cells, and bio-compatible sensors. Unlike traditional silicon chips, these materials are made from carbon-based molecules or polymers. To fully grasp how these devices operate, researchers often seek comprehensive guides on the resources. physics of organic semiconductors pdf
In inorganic semiconductors like silicon, atoms bond covalently into a rigid lattice, forming delocalized energy bands. Electrons occupy valence and conduction bands separated by a bandgap. In organic semiconductors, the physics is quite different. They consist of conjugated molecules or polymers—long chains of carbon atoms with alternating single and double bonds. This π-conjugation allows electrons to delocalize along the molecule, creating molecular orbitals: the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). The HOMO–LUMO gap is the organic analog of the bandgap.
This comprehensive guide explores the fundamental physics governing organic semiconductors, detailing their electronic structures, charge transport models, and role in modern device applications. Instead of valence and conduction bands, organic molecules
A photon creates a localized exciton in the donor phase.
For an in-depth understanding, many researchers turn to foundational textbooks. A comprehensive overview can be found in resources like Introduction to the Physics of Organic Semiconductors . 1. Fundamentals of Organic Semiconductors detailing their electronic structures
The energy difference between the HOMO and LUMO defines the fundamental electronic bandgap ( Egcap E sub g
The electronic states in organic semiconductors can be described using the molecular orbital theory, which takes into account the overlap of atomic orbitals to form molecular orbitals. The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) are the frontier orbitals that play a crucial role in determining the electronic properties of organic semiconductors.
The Physics of Organic Semiconductors: A Deep Dive into Plastic Electronics
-bonding allows for electronic excitations in the visible spectral range. Key Concepts in Organic Semiconductor Physics